I run W7 on a 2011 Mini, which still runs Mavericks (10.9.5). But the bleeding edge is also the cause of the issue, it is just named Mojave. Apple's hardware is indeed behind the 'bleeding' edge. I use a 2016 Mac running High Sierra and W10 as a VM at a major corporation. I know, buyer beware, but, seriously, 8.1 is not supported when major corporations are still on 7? Bought new fundamentally obsolescent Macbook Air Retina 2018 for $1700 just to be able to update an app submission to the store, hoped to use as PC in place of 2013 Air for everything else.