My club uses carpet squares. They usually work well. Easy (and cheap) to replace the ones that get stained or worn out.
The negative is that occasionally one will become a bit loose which creates a safety issue unless/until fixed.
It really depends upon from whom they learned 2/1. Some of the teachers here use 2M as the default rebid and some use 2NT.
As a guess, 2NT as the default (and, therefore, 2M shows six) is likely more popular.
I've played it both F1 and NF (or semi-forcing in ACBLspeak). I've played it F1 including certain very specific GF hands.
Between F1 and NF, I have a slight preference for NF, but in reality I happily play whichever partner prefers.
I do not like F1 including some ...
The war(?) against MOSCITO has nothing to do with this thread. Jeff Ford asked for input on improving the wording and checking to make sure nothing previously allowed was barred by accident.
MOSCITO wasn't allowed before, so if you want to discuss the vast Iluminari conspiracy against it ...
Perhaps something like ...
"2h. The admissibility of a call is unchanged whether or not it also shows distribution in another suit."
would get the pointy across without stepping on the accident Jeff sees lurking.