I scaled it to 150%. That’s a good size for older people who have trouble with smaller items. Nice print!

I was thinking about looking for new clips when I found this. The first clip I tried didn't grip the spool enough. The second clip worked great for a few months, but lately, it has started slipping on the spool. This should work perfectly! It grips the spool tightly. The one concern is I'm used to clips where the filament is clipped too, not just the spool. This has a hole for the filament. As long as it works though, I can get used to that!

Great idea! I wanted to add the external spool on the left side. It is a bit tricky, but it is doable. In the photos, you can see the screw that needs to be removed to switch the spool to be on the left side. I printed mine flat on the bed, minimal supports for the overhang. The radii aren't very smooth when doing it this way, so vertically may be better. Update: when I tried to remove it, it broke. So probably needs PETG, not PLA.