I designed a plate to mount the TeraXion LXM-U Laser to the optics table with good thermal contact. I used a fly cutter at 1800 rpm to get a really nice top and bottom surface finish and a 3/4" end mill to get the sides. See attached files.
I unfortunately broke a tap in one of the mounting holes and couldn't remove it. Martin Mendez in the Chemistry Machine Shop said it would take 2-3 hours of shop time to burn through the tap with the plunge EDM, costing $120-$190. Since only 2-3 holes are needed to securely mount the laser, I cut out the hole with the broken tap with the band saw.
For the other 3 #4-40 holes, I drilled them out to 0.0935" (using a #42 drill) instead of the standard 0.089" (a #43 drill) to help with the tapping. This is still plenty of thread engagement, and the tapping went much better.
I cleaned the plate with Simple Green:DI water, DI water, and isopropanol and sonication for each step. The LXM-U fits on the #4 holes, seemingly with a great contact. One of the 1/4-20 counterbored holes isn't useful as a laser input/output blocks it, but there are still 3 holes to secure the plate.