I’ve spliced a 2nd 24V fan into the wiring that provides the voltage for the (existing) exhaust 24V fan on my A250 enclosure. (My own filtration path for lasering, using it as a 2nd booster fan to help pull air thru the filter media.) Only run it a few hours total so far but haven’t noticed any issues yet, and only ever ran at 100% along with the provided fan.
I’d think a much smaller fan (assuming that’s what you’d want) for part cooling will be fine.