It is possible to publish one Jar for both Forge and Fabric: https://github.com/The-Fireplace-Minecraft-Mods/Fabric-Forge-Combined-Build Not a high priority, but seems helpful.

It's complex enough supporting six version combinations right now Forge 1.12.2/1.14.4/1.15.2 and Fabric 1.14.4/1.15.2/1.16.x-snapshot, plus that'll become 8 when 1.16.0 and 1.17.x-snapshot are released. Closing this issue for now. I'll re-open in the future if it seems feasible.