I've tested both the latest build artifact and the latest stable build and both result in memory slowly leaking, I made sure i had no other mods installed to be sure. (after about 10 minutes 5 whole gigabytes leaked.)

Hello, thanks for the report but would you provide the following things:
Envirronement: OS+java+game version+c2me build (don't say latest please ^^' it does not help and adds confusion)+an actual heap dump you can get with spark+mod list (with theit versions).
You might be aware that generating with c2me does at lot of allocations.

Sorry for wasting your time, After looking into it more it seems to be some random bug with Fabric 0.13.0, I tested it with Fabric 0.13.2 and the bug doesn't occur anymore.