Still plugging along,...bored the pilot holes out to 3/8" and 1/2" deep and inserted 3/8" plugs in epoxy. They're now a part of the solid decking.

A few days later, cut the plugs flush. Finally it was time to take the irregularities out of the decking and trim. 60 grit in a 6" RO sander was a waste of time. 40 grit did the hard work of taking off the Ipe. Then a fast pass with 60 grit to see the results. I've been anxious to get to this point:

The results are pleasing. Even with coarse 60 grit, the Ipe feels like glass. This close up of the grain shows how hard and dense it is.

Now I have(it seems) a zillion plugs to cut-epoxy-fit-dry-cut-sand,...and then there is the sole,...

All very pleasant work, at a comfortable standing height, in a warm shop. I'll never look at a teak deck the same way again, and this is only a cockpit.