What's the latest news on IOMMUs etc for the Taichi and other motherboards?

I bought a crappy A320 motherboard for my R7 1700 that’s really bad and won’t even stay stable at stock clocks (and the A320 chipset won’t allow OCs either) so I’ve decided to return it and get a proper motherboard instead (the one I would have bought eventually anyway, but that I hoped waiting with till money was a bit more plentyfull)

Anyway, I’m thinking of going with the Taichi as it got a lot of features I like.
P-state overclocking, access to a ton of sub-timings for the memory, one of the best VRMs for a AM4 motherboard, two M.2 slots, plenty of fan headers (my case got crap airflow so the more fans the merrier), Wi-Fi included stock, components that seem to be linux friendly, a second X16 PCI-e slot (not sure if it’s wired as x4 or x8, but in either case it should be enough for a Linux Host).

However the review from Level1Techs for it is rather old and didn’t seem all that promissing for IOMMU groups…
So…
I’m wondering what’s the latest news on that front for that motherboard?
I’d like to have a Linux Host running from the second x16 PCI-e slot and then run Windows from the main PCI-e X16 slot if possible.
But how is that motherboard for that now with the latest patches?
Can you set that PCI-e slot to initialize first?
How is the IOMMU groupings now?
If they’re crap what workarounds are there that works with this motherboard?

Alternativly are there other motherboards that you guys would recommend that’s less painfull to deal with?
I’m of half a mind to just go ASRock Fatal1ty AB350 Gaming K4 due to Level1Techs review of it due to its advantages with regards to IOMMU groups…
However there’s also drawbacks with that card that’s not appealing to me…
So, what do you guys know about it?
Any suggestions or recommendations?

Thanks in advance
Domaldel