It does not pin us in an impossible corner. Nowhere does is it Dogmatically taught that the people who were killed because of their professing Christianity before Baptism are saved. One must profess their belief and trust in Divine Providence. Leave everything up to His Holy Will.
Those who teach no salvation apart from water are indeed pinned in an impossible corner when confronted with martyrdom before baptism. They are forced to either be damned or deny Christ. This cannot be reasonably denied.
You pit the Church against the Church as if it was a dog chasing its tail. Acting as if the solemn magisterium infallibly teaches "conservative" truth and the UOM infallibly teaches liberal error. This is not the case and that should be obvious.
You do not trust the Church official liturgy which teaches these Saints were martyred and not baptized.
You do not trust the theologians, Fathers, Saints, Doctors and Popes.
There is no salvation outside the Church. Non-members can be saved within the Church.
I do pray that you gain the intellectual ability or honesty to grasp and accept this fact.