Thanks for the follow up. With religious life canon law specifies the amount of time given to candidacy (a formal period in initial formation unlike the way I use the term with regard to c 603), novitiate, temporary profession, and the outside limits beyond which one must either be perpetually (or solemnly) professed or dismissed from the institute. Because of the nature of formation in community and the degree of oversight and direct supervision involved, these time frames are pretty well fixed and well-recognized as prudent and also as charitable. The eremitical life differs both in kind and in the nature of its formation and degree of oversight and direct supervision allowed. As a result the time frames for discernment and formation mainly do and must also differ. While it is possible to read even very current works by canonists today who affirm that one can simply borrow the canonical regulations for life-in-community and apply them without customization to eremitical life, such an application is naïve at best and dangerously destructive at worst. Eremitical life is neither discerned nor formed in the same way cenobitical life is; to expect it to conform to the same temporal parameters is wrong-headed.
I believe this is especially true when one is trying to discern and evaluate the vocation, formation, and even readiness for profession of the chronically ill or disabled hermit precisely because one must take the time to distinguish between isolation and solitude, and also, even within this distinction, one must understand the various kinds of isolation and solitude which may be (and are likely) involved. Chronic illness always isolates in varying ways and to varying degrees. Some of these are pathological; some are not. Some may predispose to eremitical solitude, some to temporary or transitional solitude; some speak clearly of personal disintegration or decompensation while for some this very decompensation occurs as part of a radical conversion process involving self-emptying and if given appropriate spiritual direction and support in accepting the grace of God, eventual healing and reintegration of the person's core identity. But this type of process is messy and time-consuming. It does not fit in the neat canonical boxes associated with socialization and formation in community of someone in fine physical health.
Moreover, the process being discerned is about hidden dynamics because it occurs in the silence of solitude. One must look specifically for the grace of God at work in this person's life and that means looking for the paradoxical presence of grace --- wholeness revealed in brokenness, power in weakness, strength in helplessness, and independence in dependence, for instance. One must learn to look for the Life of God within the imperfect life of one whom those in non-eremitical religious life (life in community) might well reject as "unsuitable". This takes time, courage, imagination, and a well-tempered faith. The Catechism of the Catholic Church describes the hiddenness of the eremitical life. The authors did not merely mean it all happens alone (with God) behind closed doors --- though of course it mainly does this; they knew that the real fruit and processes of eremitical life (and thus, of eremitical formation and discernment) have to do with the processes of the human heart being redeemed and transfigured (made whole and holy) by the invisible God within the context of silence and personal solitude in an intimate relationship which is mainly invisible and ineffable.
Imagine this!! Read the sentence ending in "ineffable" again! THIS IS what hermits witness to. THIS is the Gospel they proclaim with their lives and very much less so with any limited ministry they may also do. Assessing this is the key to discerning an eremitical life so it is no wonder some dioceses eschew accepting anyone for a process of mutual discernment leading to admission to canonical commitment. On the other hand maybe this is better than what often happens: it is scandalous, I think, that dioceses demand hermits live this kind of hiddenness while also expecting to discern or form such vocations on the basis of criteria culled from canon law geared to the dynamics of active religious lives which are mainly not particularly hidden.
In the Letter to the Hebrews we read that Abraham trusted the promises, no matter how unbelievable they seemed, because the One who made them was trustworthy. Vicars for Religious must be open to trusting that God is at work in the individuals that come to them and allow him the time to do the kinds of miracles only he can do. After all, God is the trustworthy one here, not the time frames culled from centuries of dealing with cenobitical religious formation. Of course this also leads directly to your questions about reasonable time frames and the drawing out of processes of discernment and formation. If the usual parameters (6-12 months candidacy, 1 year pastoral novitiate and 1 year canonical novitiate, followed by temporary profession for no more than 6 years and then perpetual profession and consecration) don't work well for hermits (and especially those who are chronically ill), then what time frames are reasonable and how does one proceed in truly discerning what is happening with the hermit's formation or growth? Is canon 603 itself helpful here or, if other canonical requirements are not helpful, are we left with nothing at all to go on?
While canon 603 does not specify time frames for discernment and formation leading to profession and consecration in the ways Canon Law does for cenobitical vocations, I believe canon 603 includes the key to both quality and flexibility here in its reference to a Rule of Life the hermit will write herself. It takes time and genuine formation in the eremitical life to be able to write a liveable Rule which is authentically eremitical and faithful to one's experience of God in the silence of solitude. This is because such a Rule involves not just a statement of ways one will live the central elements of canon 603, but also relies on and articulates the hermit's own sense of the vision and spirit which drives such a life in the 21st century.
In this way, the discernment and formation process can be individually tailored and freed from the arbitrary constraints of cenobitical canonical time frames. I believe this would be particularly workable for solitary hermits, but especially for those with disabilities and chronic illnesses. Time frames would not be extended arbitrarily nor shortened in a similar way. (The period and process of discernment would need to show signs of ongoing growth in eremitical life and increasing readiness for a real and lifegiving commitment; so long as it does this the process allows for prudent patience.) Using the developing capacity to write a personal Rule in this way would mean that personnel discerning the vocation would have something objective to consider; moreover, conversations with candidates could be much more fruitful and free of bias (or the perception of bias). Meanwhile careful and judicious consideration of the work of spiritual directors, delegates, and others (including physicians and psychological screening -- if seen as helpful because of real concerns) could be used to inform a diocese's decisions in conjunction with the diocese's conversations with the hermit herself.