“She is under no obligation to follow the Psaks of Rav Shach if Chabad has a different Shitta (I have no idea what the Chabad’s psaks are in this circumstance). If the OP wishes to follow Rav Schecter or Rav Lichtenstein, she may also do so (Again I have no idea what their Psaks are in this circumstance) “
So you do not know what a Chabad Rav would pasken, and you do not know know Rav Hershel Schechter would pasken or What Rav Aharon Lichtenstien would have paskened, but you seem to be sure that this is just a chumra?
I wonder, who you do know, other than possibly Dov Linzer, would say it is muttar.