I do a lot of shore diving and never thought of attaching my fins to my BC. I have one in each hand, holding on to the ss spring strap, at the right time (depth, and between sets) I make the number 4 one leg a time and go - just a few seconds. not sure what the advantage is to attaching fins to the BC, seem like it just makes it more complicated.
note: if you're a DM/instructor helping students then maybe, but a special circumstance not just regular shore entry
Necessary when carrying a camera