Exactly well said they had to force an engine to do things it was never meant to do.If I remember correctly, BioWare decided to use Frostbite because of multiple advantages (it was not imposed by EA as many like to think). Then they discovered along the way that it was good for 1st-person view and not meant to be used for 3rd-person view. They had to tweak it a lot to achieve what they wanted.
I'm sure you've already been there: commercial engines, like any framework, always require some expected work to glue everything, and some unexpected work because there are always bugs and parts that don't work correctly no matter how good it is. But if what you want to do is in the features, that should indeed work.
When it's internal code, however, probably spaghetti code which is not documented and only working if you use it as intended… it can be quickly very complex to sort things out. I suppose it's always the question of persisting or giving up on what has already been done and choosing another framework. It's always a difficult decision.
BioWare messed up even more with Andromeda but you can't only blame Frostbite for that happening. As combat was one of the best aspects of Mass Effect: Andromeda.