Thanks again, Mike. For what its worth, here's my inlay procedure.
Started with a printout of the inlay. I made the lines .010" on the print so it would be on the line of the cut. I glued those on to the material and that helps with sanding and holding things together if the material is brittle like the jasper. If you use brittle material go thicker. On the jasper its 1..5 mm and the MOP is 1mm. They messed up my order and the black was .5mm so I routed at different depths for those. I used two blades one fine and one course. Fine for soft material, course for the harder stuff.
After everything was cut I laid down some painters tape on the fret board and got another print of the template and cut out the shapes with a razor. I taped when it was positioned and started fitting the pieces in and gluing them into place. When set, I removed the template and scored the pieces. I scored the wood. Removed the material and tape and I scored again deeper so it'll come off when you get near with the router bit. I used chalk to brighten up the lines.
From there I have a 3/32" and 1/32" bit that are spiral down cutting bits. the 3/32" bit works well keeping the material out but the 1/32" is honestly still a little messy. This is where the scoring will help a lot.
You don't want to go deeper than the width of the bit. If you do your more prone to breaking it. You'll also be able to work clean if you do multiple passes. If I can't see the edge of the side where I scored it I just get near it and leave it alone.
When the initial route is down I use thee types of razors. One with a sharp tip, hook, and rounded. My rule of thump is to try not to pull.the razors. You'll end up scoring going places you don't want to go. If the edge is scored well i'll use the rounded one to stab and turn to break it free and you'll have a nice clean accurate edge. For the really sharp corners I'll use the hook and very carefully stab the corners while pressing down.
I then try my pieces, re-score if needed and they'll fit eventually.