Practical advice on tracking collets runout, etc.

Those of you with production CNC router shops, (how) do you track toolholders and ER32 collets for runout? Practical advice wanted. FWIW, I'm cutting primarily MDF and plastics. although I talked to a guy yesterday who needs a mold from Al (nothing too precise or complex).

I measured the runout of all my toolholders and collets yesterday. Spindle was <0.0001". Some of the collets are garbage, some are bang-on. Toolholders fall into two categories - the better ones I've bought are mostly 0-1 ten-thou, the others are 2-6 ten-thou.

First, should I be labeling toolholders and collets so that I can track them and know which is which? If so, what do you use to label them?

Second, how often do you measure collet runout? How fast do they wear out and need to be replaced?

Lastly, is there a rule of thumb for how much runout is too much? I would assume a 1/2" bit can handle more runout than an 1/8" bit would. The 1/8" collets I have are showing runout of about 0.0008". That seems like a lot - do I need better collets? The 1/2" collets are all <0.0002".

Any other general/practical advice on runout?