For HALL sensor think that 15 cm is safe, but is matter of experiment, with shielded cables. Or put a MC3204 near the HALL and send the signal for controller in digital mode. With TLE50x as they work in digital mode you can use more length wire.
Make other Shift Register board is simple and cheap.
Yes, F22PRO gimbal is bad - although not bad as Cougar one made in more soft metal - and they springs dammed heavy.
I try disassemble one for try with soft springs, ball bearings... but one bolt refuse to leave this place, even broken one Allen wrench, after use WD-40, heat the place... I shelved then.
