Authentic Mystical experiences are generally associated with prayer. They should not alienate one from the sacraments or disrupt liturgy which are at the heart of one's prayer. Ordinarily one chooses the way one will pray. What I mean by this is if one occasionally wants to allow oneself to sink into quiet prayer during a liturgy, one can do that if one is practiced at doing this at other times or feels called to do so. Mystical states are something different, however. In these states, God acts to take one beyond where they are used to going in regular practiced prayer, even quiet prayer. However, two things will remain true about these periods: 1) they should not disrupt the liturgy which calls for appropriate participation, and 2) if one doesn't wish them to happen they will not. God does not force us into mystical states if we are not open to them or if they are inappropriate for the setting. I think this is particularly true in a parish setting.
You may be aware that recently a lay hermit has claimed she invariably has mystical states during liturgy (Eucharist) and she claims to no longer come to Mass because she becomes an occasion of sin for people there. I believe there are several serious problems with this analysis, and it is not sufficient to respond to these by saying "this is mystical and no one understands such things today". First, the states are said to be invariable, happening at the same place and in the same way at each liturgy. God is eternal and entirely faithful, but God is not invariable nor are prayer states he empowers within us. Moreover, significant prayer experiences are rich in content and they require time to process. It is unlikely that God would have prayer experience after prayer experience in an invariable way without the time and space to process and truly appreciate them. This actually makes them less important and less revealing; in other words, it trivializes them and calls attention to the subject having the experiences, rather than to the God who is supposed to be empowering them. What some have found to be true about authentic experiences is that a single significant "mystical" prayer experience can nourish one for the rest of one's life, so I personally disagree that this daily (or every Mass) pattern is of God.
Then we have the question of what is edifying to others and to the community as a whole. While I might very occasionally drop into more extended quiet prayer during a Mass (not an ecstasy!!), I can't do that without reassuring the persons seated with me ahead of time that I am okay should I choose to do this. I also recognize that I am a member of a praying community and for that reason, I am generally called to pray with them as we are each asked to pray together during liturgy. To do anything else (except very occasionally and in genuine need) seems to me to be a reason for staying home and praying in whatever way I feel called to. Otherwise, it is simply disedifying and potentially disturbing to my community. Finally, we have the problem of determining that these "states" are occasions of sin for someone else --- which, of course, we can never do. A person may react in a way one does not care for, especially if they are worried and don't know what is happening to us, but one does not know their motivation. One cannot know another person's heart except to the extent they reveal it to one. Even if one senses that the person is irritated or outright angry about something, one still does not know whether or not this is sinful. If the person having these "ecstatic" states is led to sin herself, then she must speak to her pastor, director, or confessor, and find a way that deals adequately with this; she can be aware of and speak of her own sin, but she cannot presume to know anyone else's.
The question of alienation from the sacraments is an important one. Personally, I find it impossible to believe that God would cause something that alienates the person from participation in and reception of the Sacraments in a general way. Why would he call one to become a member of Christ's body and then act in a way that disallows participation in that body as the Church (even minimally) requires?! Some accommodations can certainly be made in the case of illness or other extraordinary conditions, and I don't know a single pastor, priest, or other minister who would not seriously try to find such reasonable accommodations. I have a seizure disorder that is triggered by certain sounds (including some cell phone ringtones). My parish community, especially the daily Mass crew has always been very careful to be sure and leave phones in the car or at home or at least on vibrate once they understood the need. (Yes, sometimes there were slip-ups or someone new had not heard the caution yet, but generally speaking, people were really caring and responsive in this!) During Sunday liturgy, if seizure activity was a frequent problem I could have stayed in the sacristy to hear Mass, whether alone or with a friend, or I might simply have needed to stay home!
In the situation raised here, I believe that this alienation from the sacraments is feeding an essentially Gnostic approach to reality that divides it too absolutely into a spiritual (eternal) and temporal duality and leads toa spirituality that unduly maligns the temporal. (This (ancient) Gnostic duality or approach to reality also feeds alienation from what is being called "the temporal Church" and its sacramentality as well.) Given the centrality of the Incarnation along with the bodiliness of both the resurrection and the Ascension (and Mary's Assumption as well), along with the theology of the new heaven and earth where creation and God's space already partly and will one day wholly interpenetrate one another, I think this is particularly dangerous.
EEMs can always bring Communion to a person who cannot attend Mass for some valid reason. Some churches with cry rooms (or unused choir lofts, etc.) can allow someone to attend Mass from there if they need to. Ecstatic prayer is ordinarily very silent (in fact, it is awesomely profound in its silence!) so I am not sure that much accommodation is necessary if one sits at the back of the church and simply prays quietly. In other words, alienation from the Sacraments is unnecessary and unlikely to be of God. Neither, however, does this need to disrupt liturgy. Of course, if someone is making noises, crying out in pain or something, or proclaiming they can read a priest's heart in the middle of Mass, then this is objectively disedifying and not of God. In such cases, I can understand why folks might be upset and pastors might prefer the person to stay home. Still, accommodations can and will generally be made for such a person or situation. They still have rights and obligations rooted in their baptism and the Church will (must!) help find a way for the person to meet these.