This is much less likely than with deep trance hypnosis and it would be a rare thing if it happened at all. The reason is that the latter stage of meditative reverie will not allow an easy opening for extraterrestrial mischief. It is not that they cannot willfully intrude on the mind of a person. They are able to override things, but this could get noticed and they prefer to be more subtle in where and when they appear in carrying out a subterfuge of this kind. So, for the most part, they wait until someone is making themselves vulnerable in a clear fashion. When that happens, it is just too tempting to resist and then things can develop for the worse. There is no harm in doing a prayer for safety before such sessions. This is especially true when the client is someone in great emotional distress and disarray. They may already have very poor boundaries and there are always, of course, those clients very much in the grip of the Extraterrestrial Alliance directly and being actively subjugated by their efforts. You will not know this in advance in some cases because the client may not understand or appreciate this is a risk and a potential possible explanation for the difficulties in their life in coping with their negative feelings. It is better to be prepared and ask for safety across the board. It is simple to do and will reinforce a good habit at the same time.