Q. Re- prior question 2638 on the conditions Horav Shlomo Miller Shlit’a permits a front porch or backyard minyan.
1) is this a chiyuv, or only a heter, to participate in such minyanim?
2) how should non-compliance with conditions be treated?  (does it void the heter to make the minyan?)
A. Horav Shlomo Miller’s Shlit’a opinion is that if one has reasons why he should not be part of that minyan (could be medical or his relations with the neighbors etc.), he can avoid participating and daven beyichidus.
If his presence is required to make the minyan, he may just be there at the beginning of the amida and then retire inside.
Non-compliance with conditions mentioned would indeed void the heter to make the minyan.
Rabbi A. Bartfeld as advised by Horav Shlomo Miller Shlit’a