This is really well designed and works great! I did struggle a bit with a couple of assembly steps, but nothing that wasn't easy to overcome. The fit was borderline too tight for some parts, but that is way better than having things fit too loose. It was nothing that a few (gentle) whacks with a hammer couldn't solve. I printed everything in PETG except for the base and the filament guide carriage, which are PLA+.
I did a slight remix on the base by adding some mounting holes using the import negative parts feature in the slicer. I also used the slicer's text engrave feature to label the spool centering discs with the inside diameters. Finally, I designed a pair of centering discs to work with some Inland spools I have that have a recess on one side. I needed the inner diameter to be 52mm x 20mm deep and the outer diameter 100mm so the disc would not fall into the recessed opening.