This really only effects two groups:
Those in ban states with unconstitutional assault weapons bans whose only option is an “other firearm.” (These have my sympathy)
The other is douche bags who want to put a vertical fore grip without SBR/AOW stamp - not for any practical purpose but rather to start arguments and bitch when questioned by range staff who either don’t know the ins and outs of “other firearms” or don’t have magic measuring power to know the gun is > 26”.