As for the Asrock board having problems with AIO tubing, unlikely, it uses the 'Intel' 115x mounting meaning you have four mounting orientations to play with over the two orientations of the AMD mounting system. The 'keep out' zone looks good, I see nothing obivious to prevent you using an AIO considering you have 4 possible mounting orientations !!!
I'd suggest you have a good read of the thread, it might give you more insight rather than skim reading the last few pages.
I seem to be the only person talking about the Gigabyte board (SFF forum mostly discusses cases, you don't see many people talking about other hardware experiences here as they frequent other forums for that information)
There are many, many people holding out to see what the ASrock and Asus boards are actually like, this is limiting somewhat the amount of available information (on all forums tbh not just here)
Right now we know little about the other boards other than pictures and some 'analysis' !!! What I can tell you is what I have already said and that is due to the thermal and silicon limits of Zen 2, thinking there is going to be a 'Golden' board that will transcend these 'limits' is NOT going to happen !!!!
That statement isn't aimed at you personally. it's for everyone asking the same questions over and over in various parts of the forum. I appreciate there are many people asking these questions with 'limited' hardware knowledge, but I'm going to be completely honest and tell you that there are much better places you can ask these questions and get more detailed responses
One such:
https://www.reddit.com/r/sffpc/
Some thoughts of mine on the Gigabyte board from last week below !!!
You don't even need an X570 Motherboard for Zen 2, X470 and B450 work just as well, just make sure the bios is updated 'before' you try and use a 3xxx CPU with it
I wouldn't advise you go that cheap btw, it's just showing you that motherboards are not the limiting factor with Zen 2