I owned a Buffet clarinet for a while. That register key which shifted up a fifth was just too much for my bass mind.
Also I read that Coltrane used a number 5 Reed.
So I tried to progress to a #2 and couldn't blow.
It just wasn't meant to be.
#5 gotta be like blowing on a 2x4.
I had enough embouchure to play a #3.