I wouldn't classify it as abuse. It's pretty clear you are meant to survive the initial start of enrage (though likely not the entire thing). Just look at all the other successful enrage mechanics in the game and it seems more deliberate. Also, T4 has a similar "soft" enrage, perhaps it was something they were experimenting with for First Coil?

Passing rot is faster sure, but in DF it is in your best interest to go with the easiest strategy as you don't know what level of communication or skill you're going to get and Echo will not save anyone from a botched rot pass.