I hope you ragazzi don't mind me meddling in Italian forum affairs. In general, a proliferation in subfora is not a good idea I think (see
www.rcuniverse.com , a disaster if you ask me). There are not that many diy brushless messages for a new subforum. Moreover, if these discussions have their own forum, other e-pilots will not see them and will not know about the possibilities of do-it-yourself motors.
On the other hand, having all discussions and information in one place could be a plus.