Production throughput issues aside, is there any reason to not run
routers and drills as slow as they can go?

OT g

I suppose, as far as router bits go, it's related to the speed of the
cutting edge of the bit vs. the reaction speed of the material. If a
tornado can jam a straw into a tree trunk, the cutting edge of a router bit
going fast enough could cut off the waste before chipout could occur.
Thought experiment: A router bit turning at one revolution per month would
have a tendancy to split the wood, as the pressure along the grain would
build up gradually. A router bit edge at 10% of the speed of light would
probably slice off anything before the remaining material perceived at the
molecular level that it had been disconnected from the waste.

But AFAIK we don't have the materials that will hold together at 10% of the
speed of light. I know Grizzly doesn't carry a feeder that can put a piece
of pine past a router quick enough to avoid burning... g

/OT

-- Mark