Looking at what I saw (just casually), it looks like most things that had to be perfectly centered are already done. Suppressors aren't all that hard to build. If you have a lathe, even a small benchtop lathe, you can easily manufacture a suppressor from scratch. Probably the most difficult thing is the threading, which can be done on a screw cutting lathe, or just get an appropriate tap.
I've never encountered carbide drill bits, and I'm not so sure they would be all that great...once you dull them, they'd be pretty rough to sharpen. I have very little complaint of cobalt drill bits, even the cheap Harbor Freight ones are pretty darned good. I catch the big set of cobalt bits on sale at Harbor Freight on sale for $99.00 and I'm good to go (115 Pc Cobalt Drill Bit Set
When I start breaking the smaller ones, then I'll replace them one at a time as they break. Eventually, I'll just pick up another $99.00 set.
I have a Drill Doctor (FREE SHIPPING - Drill Doctor Drill Bit Sharpener for Split-Point Bits - 3/32in. Dia. to 3/4in. Dia. Bits, Model# DD750X | Drill Bit Sharpeners| Northern Tool + Equipment
That thing is worth it's weight in gold to someone who does a lot of metal work. If you're a gunsmith, machinist, or mechanic, I just think a Drill Doctor is an absolute must. To me it's just WAY easier than sharpening on your bench grinder, more accurate, faster, etc; and the bits always come out perfect.
The only down side to the Chinese Harbor Freight cobalt drill bits is, sometimes (I'd say about 1 in 30) they're not properly sharpened, so the Drill Doctor makes that right in a jiff.