This spooler works smoothly and without incident for long prints and filament sanity. Printed well, the parts fit together without adhesive.
To make it, I took CTR/CTRLyourself's simple design, created a base for the two triangular bases, and merged them together with a thin middle to allow flexibility when inserting a filament spool. Then I raised the vertical arms by 8mm to allow more spools to fit.
Printed w/ PLA, .3 layer height, 2 shells, loose infill
Simple spool holder