the spring on the Ender 3 allows filament to slip. This results in a 1st layer that does not print evenly. This adds about 2mm of extra tension to the spring. I had to put a 5mm drill bit in the center hole to ream out excessive plastic. If you feel more tension is needed use one at each end of the spring.

There is a new remix here https://www.thingiverse.com/thing:4815873 as well