I have a Gitzo tripod with an extendable arm that I use to photograph flat artworks from overhead. My whole setup (see image) works perfectly except for one thing: Because I set it up and take it down as I need it (no dedicated space) I am constantly having to fiddle with it to level the camera to the surface. I am doing this with a hand-held level and adjusting a little this way and that. The current head is a little stiff, and ideally what I'd like is a head that can make fine adjustments with a dial, instead of un-tightening, nudging, tightening all the time.
Something like the Manfrotto XPRO Geared 3-Way Pan/Tilt Head. https://www.bhphotovideo.com/c/product/1124273-REG/manfrotto_mhxpro_3wg_xpro_geared_3_way.html
The question is, will that fit my tripod and can it be attached at the end of the tripod arm (where I've drawn a red arrow in the photo)?
Advice or suggestions?