Improving Z-axis height via gearing? (Printer modding)

Hi all.

I'm in the process of doing some extensive custom modifications to my Neptune 4 Max, including replacing the POM wheels on the Z-axis with 10mm Linear Rods (I can't justify the cost of the Linear Rail modification kit, and this is more fun anyway).

As part of my modification, I need to move the location of the Z-axis stepper motors. One of the things I'm chasing is a better Z-axis accuracy as I plan on using a 0.2mm nozzle (yes I know, big printer, tiny nozzle lol) to print thin, material-like layers - goal is 0.04mm but honestly I'm all about pushing the limits of what's possible (which I'm aware will also require print bed flattening - lets just assume I've taken all other needed modifications into consideration lol).

I know some printers, like my Creality K1C use gearing on their Z-axis. I'm wondering if I can use gearing by separating the lead screws from the stepper motors via a timing belt and using a larger 80 tooth pulley geared to a 20 tooth on the lead screw.

Are there any cons to doing this such as issues with backlash? I'm aware I'd need to change the values in Klipper in regards to steps per mm (or whatever its called) and I'd want to make sure my lead screw mounts are bang-on to prevent banding, but are there any other considerations I need to think of? Would the gearing actually help with accuracy or would other physical limitations of the printer become a bottleneck Also, would it be still worth de-coupling the lead screws from the stepper motor and attaching them via a belt? Heck, would mounting the stepper motors to the top of the gantry instead of the bottom reduce potential banding/leadscrew wobble?

I swear, working on this damn printer has made me appreciate the level of engineering that goes into the more expensive CoreXY printers vs the cheap bedslingers lol