This DMT 2.0 mod re-enables the prefab menu (K) when debug mode (dm) is enabled, like it was in previous versions.
This is a DMT mod. So requires DMT Modding Tool.
Just in case people haven’t noticed, there is a “Block Replace Tool” available in the creative menu when developer blocks are active. It contains some of the original prefab menu functionality, which may be enough for your purposes (and doesn’t require a DMT mod / disabling EAC). If it doesn’t contain everything you need, or you just prefer the old method of doing things, then go ahead and grab this mod.
The forum topic of the mod is here.