With care and going slowly one can cut the rectangular opening in acrylic precisely with an X-Y table and a drill press going sideways but one is going to need to use a fine hand file to get the square corners. A diamond file with a square corner will do it handily.
You can always rough cut the rectangular openings and then do the final trim with a smaller diameter bit.
The motor is fairly high RPM and this is a good thing when cutting plastic.
I don't imagine it will hold very tight tolerances but it will probably be good enough for panels.
For doing this I want to be able to temporarily affix (glue?) my laser printed out template to my piece of plastic.
glue it well enough to not tear when the holes are being drilled and filed, and then come off completely in soap and water without my having to scratch it.
Kind of like with toner transfer PCBs except with the omission of the scratching of the PCB and heat and toner and the substitution of elmers glue. (Its all Ive got, and it seems to be water soluble enough to not require my scratching it to get it off, given enough time)
Elmers glue to glue it on, and later soaking and maybe toothbrush to get it off?