I finally went out to the park to use the public bike stand. So the question had been if the chainline is 1mm longer, would I be able to access the large chainring. After playing around with limit screws eventually I decided to undo the bolt holding the front derailleur cable and add or subtract cable tension with the limit screws being either at the bottom height or middle height. I had the screws around middle height when I finally got it to a point where I could shift to all 3 chainrings and also not rub too much either on the inside or outside of the FD cage. Even though I don't think I had it absolutely perfect, I was satisfied since I was ouitside in the heat and could barely concentrate.
Now I'm satisfied I can roll. I don't know when I'll make a video showing how I modifed a department store bike though. I think it would be interesting for others to see.