ASA warping where supports are  

ASA warping where supports are

Hiya, I'm trying to print this in ASA:
https://www.thingiverse.com/thing:6850212

This has a few critical areas that need to be accurate, but also need to be printed off supports, specifically these corners:

I've already printed this in one piece and the above two screen shots show where the part separated from the supports, I used Organic supports with a 0.2mm top contact Z distance.

The larger opening I reckon I can just add a simple mesh/box to bind that corner to the bed & cut the additional block off post print. The smaller opening is problematic though, from what I can see that has to be done via supports as it's 5-10mm inside/below the level so cannot be easily cut off post print, that needs to be accurate as a 'thing' gets plugged into that section and will otherwise flap around.

Bed adhesion isn't a problem - I'm using a Satin sheet with a spray.

I'm using Elegoo ASA filament with the Prusament ASA profile (made adjustments to the density as the Prusa was slightly less dense than the Elegoo) but other than that stock Prusament ASA settings.

Layer height 0.3mm on 0.4mm CHT.

I can't print it face down as the side mounting tabs are slightly raised from the main face and on those mounting tabs are two pins that stick up 3-4mm, there's also a small lip running along the bottom edge.

I have thought about splitting it into two bodies so I can print the front half flat on the bed and the back half front-down so minimal supports are needed,though this would bring a different set of issues I think as there are sections that are not in plane with each other and would require thin/small layers of support material.

Any suggestions about how to approach this?

Thanks.