I used coinomi myself, it was simple as you did with electron cash, just import seed, add forked coin and balance equivalent to btc held during snapshot would show up.
Coinomi is under suspicions these days but shouldn't be worry since you gonna transfer coins immediately to HW.
Edit:
So I read I can still claim bitcoin sv and bitcoin gold
Import your seed in coinomi, select these two from list of coins, your airdropped coins should show up.
Now the thing is where would you then send the bitcoin gold to?
Convert it to btc and send it your ledger through
https://swapspace.co/Do same with Bitcoin SV.
I have no idea about Bitcoin diamond and ecash, wait other users responses.