I modified the side mounted spool holder that comes on the USB drive of the Ender-3V3Plus to better fit my print farm set up. The original was flat (see side by side comparison photo original on the left) making the post stick out too much making it difficult for me to slide a spool on/off it due to the lack of space on my printer shelf. So I modified the base bringing the spool in closer to the build plate by about an inch for a more compact set up. Nothing fancy, but it helped my print farm and thought I'd share in case someone else has too little space.
To install, just use the spool post from the printer and twist it into place then loosen the side screws a bit, slide this on and tighten the screws to hold.
I printed as shown at .2 layer height with normal supports, 3 walls and 5% honeycomb infill on my Creality Hi in PLA.