I would be concerned about ditching the X570 chipset fan (with no cooling replacement?). They didn't add the fan for fun. B550 boards are available fanless and have most of the same features.
From reading lots of reviews and what not, the chipset fan on the X570 is really only needed when doing a lot of PCI-e 4.0 stuff; the CPU in question doesn't support 4.0, so it really shouldn't be an issue to disable the fan. Although buying a less capable board is probably a better answer; personally, I built my SFF system on an A520 board, the only down side is very little overclocking/underclocking/voltage tuning support. There is some support for tuning, but you can't use the best utilities, and so I'm just running at stock which works well for me, but a small undervolt might give similar performance with a little less heat.
