I have a all steel 6090 cnc router, i need do about 300 holes on a 6082-t6 20mm thick sheet.
I already order some carbide drills but calculator is giving high feeds which is not good for my machine, so i'm asking for advices how to do this job.

Holes size: 7.5mm
DOC: 20mm

Using HSMAdvisor i got these: https://i.imgur.com/QBinlal.png

The feed is high for my machine under a plunge and it want more but is limited by my machine max feed so i have to reduce that feed. Also my chinese spindle is only 0.8Nm given the specs which i'm always used to never use max values because we never know if the specs are true.

Using half feedrate i got this: https://i.imgur.com/I7CMM5Z.png
It is safe to use that at same RPMs?
If possible i would like even slower...
NOTE: Ignore peck on calculator, i plan to do full hole height (20mm) with carbide ()


Also i like to know which strategy is best:

1) Start with lower drill, like 4mm and redo with 7.5mm. (Is this way easier to machine?)
2) Use only the 7.5mm drill (same size as hole)
3) mill instead of drill?
4) drill with endmill pecks?