Horrible if original Electrum would start supporting random shitcoins.
There is a seperate version (fork) for Bcash called "Electron Cash" but original Electrum is for Bitcoin.
I don't know for BSC, maybe Exodus is an option but it's closed source and fees can't be modified.
There are forked electrum for almost all forks. But they do not hold any relationship with Electrum.org team, neither electrum cash.
For example, if you google Electrum Diamond, Electrum Bitcore, etc you will find electrum for all those forks (i will not share their website because I don't know iff they are safe to use). But none of them were credited to the same team from Electrum.org
Binance altcoin is not even an Bitcoin fork, so there is really zero chance electrum would support it...