Firstly, everyone holds at least b’dieved that one can daven after Shkiyah during Bein HaShamashos. The time l’chumra (obviously for non-Chasidim) brought down in the Piskei Teshuvos is 13 1/2 minutes I believe. Reb Moshe says in his teshuvos 30 minutes – can’t find at moment but saw inside [not sure if that is ending by or starting by].
See the last Mishnah Berurah on second page going on Rema that explicitly says that one can daven until Tzeis Hachovim. M’B says (b’evived/shas hadchak) until 1/4 hour before Tzeis (I saw quoted that R’ Ovadiah Yosef says until Tzeis literally so seems the lashon of the Rema and Kitzur Shulchan Aruch who brings it down) and that if there are 3 stars it’s certainly too late. So that’d be around the 30 minute mark of Reb Moshe in America I think (assuming early ‘Tzeis’ of 42/45/50 minutes).
So for sure they have what to rely on b’evided [and obviously they are going like poskim/ their mesorah that holds it is l’chatchilah after shkiyah] until early tzeis. So helping would not be lifnei ever at all IMHO.
DQB