Cheap rail adapter back in stock (too late for me?)

Unicycle.com finallly has an affordable rail-type seatpost adapter (it’s been out of stock for a while). Problem is, I’ve already drilled my CF seatbase to accomodate a miyata seatpost.

Is it safe to drill new holes for this adapter, or would that weaken the CF seatbase too much?

Also, any recommendations for a 22.2mm rail-type seatpost? (Unicycle.com only has one).

(bump for a fellow hell on wheeler)

A friend of mine has drilled the miyata-style holes, then changed his seat setup and now has the 4-holes like the KH and Kinport rail-adapter. He does hardcore downhill, and the carbon base hold up very well and didn’t cracked. So I guess it doesn’t weaken that much the carbonfiber base.
Be sure to put something between the base and the rail-adapter tough, because the two have not the same curve.

Unless you have a KH CF base!