How to copy and past selected verticals to same edges?

just trying avoid extra work
12312123

Welcome, @Jounsel_Warpig!
It would be simpler if you just pressed ‘Ctrl-R’ to add loop cuts instead of duplicating.

I second that motion and would add: scroll the mouse wheel after hitting Cntrl+r to add multiple loops/edges at once.

If you also select an existing edge/loop and hit “g” twice, you can drag it along.