Did you notice a difference in print speed when you slowed down? As this is a small print, it could already be as slow as it will be due to minimum layer times.
It could also be that the nozzle spends too much close to the print. What happens if you print 2 or 3 of them?
This is typically more of an issue with PC where you don’t have a part cooling fan running, but maybe it’s the case here too?
Interesting that the extra 10° makes such a difference for ASA and ABS.
I recently started printing with ASA in my enclosed MK4. I might have to try this.
Could you explain what you mean by “full commercial use”?
I would model the part myself, print it myself and check for fit and function. Once the part design and tolerances confirmed, I would then either use a local or remote shop.
Xometry.eu (no affiliation, never used them) appears to be in Europe and outsources to local shops. They have plastic and metal SLS, CNC, sheet metal, and everything else as possibilities. https://xometry.eu/en/direct-metal-laser-sintering/
Another option is to use the Chinese PCB shops. PCBWay has amazing abilities these days: https://www.pcbway.com/rapid-prototyping/manufacture/?type=3&reffercode=TOP
It could be a case of too much cooling, while simultaneously being too much heat.
If you’re blowing so much air that the filament instantly solidifies when it leaves the nozzle, it’s not going to bond with anything else. It’s also interesting that the first layers are fine (when the part cooling fan is typically not running), but problems start when the part cooling fan turns on.
Have you tried without part cooling at all? Another thing is that your part cooling might be cooling down the tip of the nozzle, causing tiny partial clogs, which are cleared every so often by friction.