Ryzbor, if you mean to use some ∅22mm Convoy SST-40 linear driver (12 groups or 4 modes) in a Manta Ray C8.2, could work. The drivers may need some modification to work properly with 2S cells, but if they're built with the same parts as other recent Convoy drivers they'll likely straight work fine. Check the Convoy XHP35 Driver Analysis / Testing / Schematic thread, onboard linear regulator investigation here.
The increased voltage drop in the MOSFETs could cause trouble, improve driver cooling as much as possible.