My experience with Duckworth Installation
I drilled the Plexiglass with a fairly well used #30 or 40, at a medium to low speed and very little pressure, then I used the Unibit, and once again the amount you push will almost be imperceptible. Your really should gauge how fast to feed it by looking for just a little bit of very thin plastic curl coming off the bit.
A variable speed drill is a must.
(If your building an RV I would hope you already have one.)
The weight of even a small hand drill could be too much pressure, so keep it light.
You will always be able to add more pressure if necessary, but once you crack it. you can't add less.
The analogy is like cutting a rope,
"I cut the rope three times and its still too short"
The instructions I thought I read (years ago) did not include drilling rivet holes in the plexiglass, just the metal nutplate strips. If not thats the way I did it.
The metal strips can be fastened to the plexiglass with a small amount of clear silicone, and held in place with the screws and Large area washers until cured.
Hope this helps, have fun, and