Effect Icons on Tokens

For the longest time, I've been trying to write an extension to add functionality for token effect icons (those small icons on the lower left corner of tokens on a battle-map, indicating some sort of condition is active) so they work outside of officially supported rulesets like 5E or PFRPG. As far as I can tell, the code for this is somewhere in CoreRPG, I just can't figure out where. Has anyone here had any success in getting this functionality to work? Is anyone able to point me to where in the code this is handled?

MOD: moved to the workshop. I think you will find more knowledgeable folks here than in the CoreRPG forum.

I am pretty sure some existing extensions have modified the effects icons, so hopefully one of those devs will be along to give you some good info.

Good Day All :)
:::Looks around::: Umm LordEntrails, I believe this is Extensions not Workshop. :)