If I might offer:
I Worked in the Marine boating industry for quite a few years. Fiberglass is no stranger to me.
Your hard top is made of a fiberglass reinforced resin. It wont respond well to fast moving cutters. Too much heat build up.
The best thing to use is a good old cheap hand held jigsaw.
One with a variable speed is best. They make different blades for them . look for a fiberglass/plastic blade. A small toothed wood blade will do if you cant find that.
Then make sure you put masking tape down on all your cuts.Mark the tape and cut through it.
This will help prevent chips and scratches.
Use the jig on a medium/low speed.
Start by drilling a hole inside the line and move out .
Easy Peasy.