The answer is yes - if you check it out on an unconected PC. I haven't had a real play with it, but on G90 it goes the shortest way to the required position. On G91 the move is incremental to the posiition you are at so moves in the 0 - 180 bracket move you forward, moves in the 180 to 360 bracket move you in reverse. However - say you are at 10 degrees - G0 A10 moves you to 20, G0 A350 moves you to 0.
Is there something deep in that - or could you just use G0 A-10 instead