Choosing a wheel upgrade

Hunt do a carbon disc brake wheelset 30mm external 23mm internal

i know from my DT RR521 (21mm) internal that they make a 25mm tyre into a 28 wide fitted.   So its likely that the Hunts would do the same to a 28 mm tyre giving a wide aero setup

If the tyres are wider than the wheel rims then you basically negate any aerodynamic benefit the deep rims provide. I doubt there are any aero wheels that'd fit on a road bike that are wider than 32mm. If you want aero wheels and benefit from the aerodynamics you usually need to use 23 or 25mm tyres as there aren't many wheels out there that are wider than 28mm.

Don't forget as well that wide rims have a habit of stretching tyres, especially ones that size large like GP4000's. 

I have Bontrager TLR wheels and went tubeless on them - I found that the seal was great however the rims do not hold the beads in place when the tyre is fully deflated, which means you will have to take a spare tube with you.  Worth checking if that is the case for the  Aeolus.

Difficult to compare Flo with Roval and Bontrager. Roval is owned by Specialized so you're paying for the brand name whereas Flo only sells only online. Bontrager is Trek's brand so it's a bit like Roval.

Tbh, I tried Flo but didn't like it at all, just seemed like a poorly designed open mould. On top of that you have to pay import costs and taxes, I wouldn't recommend it. Other people loved them, though.

Think a lot before going tubeless, make sure you talk to people who actually use them. It's great as long as you don't have any issues - but when you do it's not as simple as changing a clincher. If you do want to go tubeless, make sure the wheels are "tubeless ready" and not just "tubeless compatible".

Road wheels are unlikely to support 32 tyres. You should look into gravel or cyclocross wheels instead.