Quoted from wrd1972_PinDoc:So in the video he is using a sanding drum and not a router bit. I can see the sanding drum being okay for after the HT is stuck because I cant really see the dust getting getting forced under the HT. The router chips may be a different story. Again I am speculating that this may be an issue. I don't know because I have never tried it.
On the last couple hard tops I have stuck, there were areas in the HT around the holes that did not have adhesive. So if there is no adhesive, you now have a very small clearance or pocket for the chips to get forced into. If this were to happen, you would have to dig the chips out. Also, in the video, there is no missing adhesive around that insert, so there is no risk at all there.
IMO the safest way to go is to clamp the HT and route the holes out, and then stick it. If you align the HT properly and clamp it before sticking it, it will go on perfectly.
OK, I see your concern about debris getting permanently stuck between the HT and the PF.
I was just looking over my HT with that in mind, I did not see any hole I need to route where the adhesive is not completely encircling the hole.
The worst case scenario I can imagine is routing all the holes and then sticking the HT off kilter.
Maybe I'm just over thinking as usual.