Solution: The problem was that I installed Holowan Duplisaber to the Steam game folder. If using TSLRCM and M-4-78, non-workshop mods have to be installed to those mods' folders.
Just installed this on the Steam version, running Steam mods TSLRCM 1.8.4, M4-78 Enhancement Project, and the Content Pack: Feats and Powers.
I don't get a "Saber Console" option at any workbench, but it has changed the sabers in my inventory to hilts from this mod (and the crystals in them as well).
I installed the Steam mod "Skip Peragus", which does what it sounds like, and provides you with a saber. I started a new game, skipped to the end of Peragus, then tried the workbench in the Ebon Hawk and still didn't get a Saber Console option.
Any suggestions?