Found this Ender V3 SE/KE spool base on Thingverse and remixed it for use with a universal spool holder. You can screw in an 8mm threaded rod and I would use at least a 120mm length on the rod to account for the base and universal spool. I used a little bit of glue to secure the rod to the base. I also used this modified M8 Nut to cap off the spool.
Link to M8 Nut:
Screw Set M3 M4 M5 M6 M7 M8 M10, ISO 4017 by Jerryie
Link to base:
Porta bobinas de filamento de grandes dimensiones by goyenechesco - Thingiverse
Link to Universal Spool Holder, I used the short spool + spool nut which fit a 120mm rod perfectly with this modified base.
Universal Filament Spool Holder by butchja - Thingiverse
I personally used this with the side spool holder here, but it should also work with the original spool holder.
Side spool holder with anti shake construction - Ender 3 v3 KE by Sano
The author remixed this model.
@Jerryie - Remixed the M8 Nut to fill the bottom and use as a cap.
@goyenechesco https://www.thingiverse.com/goyenechesco for the Ender Spool Base
@butchja https://www.thingiverse.com/butchja for the Universal Spool Holder
@Sano for the Side Spool Holder