I measured the following waves:
C1:BSWV WVTP,SQUARE,FRQ,500,AMP,0.60000000000000013,OFST,0.30000000000000006,DUTY,50
C1:BSWV WVTP,SQUARE,FRQ,500,AMP,0.7,OFST,0.35,DUTY,50
C1:BSWV WVTP,SQUARE,FRQ,500,AMP,0.8,OFST,0.4,DUTY,50
C1:BSWV WVTP,SQUARE,FRQ,500,AMP,1,OFST,0.5,DUTY,50
C1:BSWV WVTP,SQUARE,FRQ,500,AMP,1.2000000000000002,OFST,0.60000000000000013,DUTY,50
C1:BSWV WVTP,SQUARE,FRQ,500,AMP,1.3999999999999998,OFST,0.7,DUTY,50
C1:BSWV WVTP,SQUARE,FRQ,500,AMP,1.6,OFST,0.8,DUTY,50
The bottoms should all be at the V-centre, but when having more voltage offscreen, the center voltage "rises". This happens with even small voltages like 300mv. 3 times the V/div. Because there is almost 1 division of digital margin offscreen it is almost nothing beyond that.
Maybe I made a mistake, so I posted the AWG commands.