It’s really no one’s business when anyone takes off their t’filin or leaves before the end of davining. The SA allows the taking off of t’filin after “Uvah L’tzion” so don’t be frummer than the SA.
And m’ikor hadin one does not have to say everything written in the sidder if you don’t have the time, but find out what you can omit.
I think it’s great that yiden can come to minyan at all so if they need to leave early, that’s ok with me. Personally, I’m there in the morning an hour before shachris and don’t hurry home after maariv, but to each his own.