There's a rather disedifying story about Archbishop Lefebvre.  +Lefebvre, having visited a missionary area, as he was leaving, was acosted by a native who asked if +Lefebvre could baptize him, since he was worried about not being saved if he died before +Lefebvre's next visit (which was some time off).  See, if that were me, I'd be like "this man has more faith than most Traditional Catholics" and then baptize him right there.  But +Lefebvre told him not to worry about it because if he died before then that Baptism of Desire would take care of it.  So ... by telling him this, it turned a zealous desire to be baptized that if there WERE a BoD, that's precisely the kind of zeal and ardent desire (and intention) needed for it to take effect.  But now this poor soul, having "relax" ... would have stopped desiring it with the same zeal as before, and quite possibly jeopardized his ability to be saved by BoD (if it existed).

Yes.  That’s why the attack on EENS started centuries ago.  EENS has been under attack for millennia, which is why the Church has had to define it THREE different times.  (And needs to redefine it a 4th time).