FT shooter for Tech

[letemplay]

Team A, nursing a 3-5 point lead in closing minutes, is subbing A1, their best ball handler and free throw shooter, in and out for offense/defense purposes due to having four fouls. With A1 in game, B1 is called for common foul sending A2 to line for 1 and 1, where upon A1 is subbed for by A6. Prior to A2's free throw, B HC is hit with a T. May A's coach designate A1 to shoot free throws, returning as an eligible sub as in 8-3? Can he return only to shoot technical free throws, but not be in game when ball is put back into play, until clock has ticked?