re: Scribing in, how do you do yours?

I guess I’m a butcher compared to your method, which is probably more proper.
I usually rabbit the back of my scribe pc so that I’m cutting 1/4 thick. I tape up the face of my pc, draw the scribe line and follow it with my jigsaw. This works for me because the 1/4" is easy to cut through, I always start with a fresh blade and I’m pretty good at following a line. A quick swipe with a sanding block and presto. I just have to clean my mess when I’m done. At times I have used my belt sander to sneak up to the line when there isn’t enough meat to hold the jigsaw. I have to do this outside though, don’t own a festool. I do have a small hand plane to take it to the line but don’t find myself using it that often.
Here’s what I use for a scribe pencil, it doesn’t mark the walls.