I just finished my ATC build, and plan to utilize warm up routines.
I completed writing and testing one such routine for the CNC itself, and that is working well. I am now writing one for my spindle.

My question is: should I warm up the spindle as is, with only a balanced tool holder in place, or with a tool holder, precision ER collet, and an end mill?
As is often the case, the manufacturer videos, user videos, and online articles I have explored to date have examples of all three of the above.

I have a 24K RPM 2.2Kw water cooled ATC ISO 20 spindle. I am just starting out, and have little of my own milling experience to date, so I would be happy to hear from anyone with experience to share on this topic.
Insights from users of this type of spindle in particular would be valuable with respect to their best practices for warm up routines.

Thank you,

Tom