I have crimp connectors that are bigger one end than the other so one wire in one end and two wires out the other, there is a good array of connectors available. Have added a lot of electrics over the years, only Issue I had was with day lights I fitted and used one of those crap things to pick up power many years ago, never again.Neat set up bud, which one of those would you uses when you want to join the end of a wire to the middle of an existing wire.that’s what’s happ
Depending where the wires are I also use heat shrink.