So I found a great spool holder for the MP Select Mini but it wasn’t perfect, I had to redesign or remix it. I found that the most spools rub on the bracket so I made it longer and I raised it slightly as well. Now it’s perfect in my opinion.

Here’s the original on the right and mine on the left to compare:

Here’s the link on Thingiverse:

Monoprice MP Select Mini Spool Holder Remixed Larger and Longer
https://www.thingiverse.com/thing:2453242