Jump height is determined on the first aerial frame of grounded jump like in Project M. So if you perform a grounded jump with fox, releasing jump input by frame 4 is sufficient to short hop, instead of having to release the button by frame 3. Otherwise jump physics still work like in melee, and control stick influence to horizontal speed still depends on the input received for the last frame of jumpsquat.
Code:
$Extended SH Jump Input Release Window [tauKhan]
040CB2CC 60000000
040CB168 C03F0628
040CB1F8 98010028
C20CB34C 00000010
83E3002C A09F03E8
2C040000 40820068
7FE4FB78 3D80800C
618CB640 9421FFE0
93E1001C 48000014
7FE802A6 93E10024
7D8803A6 4E800020
4BFFFFF1 807F0000
3821FFF8 C02294DC
38800001 3D80800C
618CB110 7D8903A6
4E800421 38210008
889F0671 2C040000
4182000C 8881FFF8
989F0671 7FC3F378
60000000 00000000