"When could this flag be implanted? As the project I'm on needs bones with weighted vertex that I'm willing to make them myself if needed. "

it is for that trials exists!
before buying a game engine you have to see in first place if it has the feture that you desire (vertex weights)
mainly when "this engine" says to be "PROFESSIONAL" > without multiple vertex weights > it only can be joke !!!

conitec says that it plans this already some years!!!

a majority of the BAD animators who use A6 does not know what weight vertex is !!!