so I am currently playing a game with a custum faction based of the horatio template but when I finally got this tech I couldn't find the option to reform any of my minor faction pops into my main faction.

Is this a known bug or am I doing something wrong?

Normally it should show up in the system buildables like Chain Gang & other improvements do, Is it not showing up there?

no nothing like that, currently playing but it doesn't show up

Are you sure you are not trying to use this tech in a planet that has no minor population? (Even then, the tech should be greyed out and not completely invisible)