It's confusing. As I read more, I understand that MIUI 10 is 8.x.x branch of the ROM. This ROM is only available in beta...
Then there is de MIUI 9 version, that would be the 9.x.x branch of the ROM.. Weird to have a newer version on a lower version number, but ok, I guess that is what it is...
Now Xiaomi has enabled the newer anti-rollback feature, also referred to as V4... You cannot install anything older, so you would need a ROM with V4 security or you will brick your device... However. It is totally unclear what EU ROM contains V4... I'm guessing it isn't available at all just now.. But it would be better if the developers created a post explaining all this and telling us what to do... At this time I'm happy to wait another couple of weeks for a new EU ROM that is installable on my Redmi 6 pro... Don't want to risk bricking it at all...
Also, I'm not so keen on MIUI 10 now either, having an EU ROM with MIUI 9 would be just fine at this moment...
So, xiaomi.eu devs, please, give us the clarity we need
And ultimately, please provide us a installable ROM that doesn't brick our devices :-D
Thanks!