Would be nice to be able to add the global quality to building from other mods. Maybe by imputing their building names in a text bar separated by commas in the settings.

Otherwise liked the mod and had no issues.

Uhhhh...
Modded buildings should already have base quality...

Reverse factory 1, 2, and 3 from Reverse Factory mod didn't. The extra info on the tool tip that tells what mods are affecting the item only shows Reverse Factory mod. Other buildings like assemblers show "Base mod > Space age > Quality Assurance" when looking at the tool tip. So I assume that means the Reverse Factories were never changed by your mod. If it helps, the Reverse Factory is based on the FurnacePrototype.

Huh... well this is a tough one...

Fixed in 1.4.1. There might still be modded buildings which don't have Base Quality, but this update should fix most of them.