Avoid 3 flute - 2 flute or less for Alu - unless you user roughers like this which work very well - https://www.shop-apt.co.uk/3-flute-r...d-carbide.html - can go 8mm too - cheaper / easier.

HSS wont serve you well, dont bother with it.

2500 - 3000 mm/min is quick. I wonder if your spindle will bog down with this. the WOC is nice and narrow - you could try that at 10% with even a deeper DOC but Id runs slower feeds on that.

You are probably going to find that the problem is that you cant get the chips cleared - 3 flute is not as good (unless using a rougher as it breaks the chips into things that look like oversized dust).

Those feeds would work on 3 flute but chip evac is an issue.

At 24K RPM on something like a 6mm endmill (2 flute) Id run along at 1200-1500 with 20% WOC and a 10mm DOC. Endmills like working deep when doing adaptive paths - use all the of the cutting surface. Then work out how fast / wide you can go. The smaller the endmill the faster you need to spin. I'd never run your 2.2 KW under 24K RPM on Alu - no point. Dont be scared to feed quicker but only if you can get the chips out.

For 2 flute id be looking at this range - https://www.shop-apt.co.uk/end-mills...d-carbide.html - probably the 8mm or 10mm. Ditch the 3 flute stuff, its the main problem you are having.