I do think that the transfer of both technology and technique for sidemount diving, from a relatively limited number of divers in the cave community to the larger (predominantly backmount-oriented) technical diving community, and to the even larger recreational diving community, at least as far as backgas goes, is in a period of early and rapid development...
...But, there is almost an explosion of SM commercial technology and training taking place right now, and SM is 'hot'. Whether that is sustained or not remains to be seen (I suspect it will be).