I don't think anyone is questioning if more is possible. I think following the lead of the PSP is what people are looking for. It makes sense if the intent is to graduate them up level to level and if any of them intend to play PSP at any level now or in the future. A good rule of sports is practice like you play. Playing 15 BPS local tourneys won't help a lot for teams wanting to play PSP at 10 BPS.
I hate to put hardship on the newer teams but L4 is pretty self policing with the one battery rule as it is. L3...well I don't have the answer for that one. Less BPS makes no difference to my kids as they play L3 on just 2 cases of paint in a tourney.