As I have repeatedly looked at the endless array of PF1 feats…each more niche than the last, I can respect the concern.I disagree, but of course I didn't reply to your comment. I mean PF2 is built completely on the idea of everything (almost) is a class feat and it works great. Personally I don't care for multiclass feats because we don't use multiclassing, so they are waste for us. But that doesn't make them a bad idea.
5e feats are based on general flexibility. Most of them (the good ones anyway) combine several niche abilities with minimal prerequisites to create widely usable feats. That was a distinctive design choice. It is easy design wise to start making specific feats, to create niche abilities…but that leads to more and more pages of mechanics fewer and fewer players can use. The harder but more rewarding path to me is to stay in the more general sphere.
Now a feat that requires multiclassing I can respect. Multiclassing is an odd duck, especially mixing casters and martial. So feats in that realm as a portion of the total package seem fine to me. After all LU is intended to add crunch in areas that O5e doesn’t always cover.
that said, I agree with others that the specific classes here seem an unnecessary straight jacket, an attempt to tie a “very specific flavor” to these mechanics, and I do think that’s a concern.
what is wrong with a barb/sorcerer having this option? Now it’s int based so it’s probably not going to be all that great at it…but hey if your playing the weird smart and charismatic barb with magic power…enjoy your bonus!