Setting for cutting half inch acrylic resin

I used to cut it on our 40w Full Spectrum all the time, 2 passes of 6mm/s, 90% power.
100w should be able to punch through at 60% or so power depending on the machine. Focal length of your lens would affect speed and quality of the cut, but I would start out at 10mm/s single pass. Do a couple small lines into the edge of some scrap, and you will see how much penetration you are getting at each speed (if this is not a case of being charged for laser by the minute or having them run your files)

I also have a 40W machine and have cut 10mm at about 5mm/s@100% drawing 20mA. I used a 4" lens focused at the middle of the material.
A 4" lens is too short for 12.5mm, it’s depth of focus is just over 10mm.
If you have only 1 piece that’s got to be right, I don’t know what to tell you. Even if all us had equivalent machines it’s unlikely that the settings would be the same.
Good luck