Heh I could, but a bit of back of the envelope maths shows that I'd really be pushing it. It's an old gold rated PSU, so I think it would be borderline on balanced mode with my rig and trip on turbo especially under gaming load. I've only had crashes in The Witcher 3 and XCom 2 but... they're the games I've played the most. Perhaps I'll devote some solid playtime tomorrow into Batman or Nier Automata.
I've been away from the forum for a bit due to life stuff dragging me away. That doesn't mean that I haven't devoted a whole load of time to tinkering with my PC and the Vega 64 though. The tl;dr; on all the latter problems I had with stability was, as far as I can tell, the fault of my CPU overclock. Hence it being stable at stock once I'd solved the cabling/driver issues. After much much tinkering, and swearing for not keeping a written copy of the bios settings I had, I'm at the point where it's normal again.
The upshot of it all is, not only do I know have a shiny new GPU I have an improved PC as a whole. I've managed to get a stable faster overclock; having remounted the cooler and discovered I had way too much TIM on there, to learning more than I ever wanted to know about Asus BIOS settings, how adaptive voltage works and various other bits and pieces.
Much of my problem after updating the PCs BIOS and wiping out my settings was beginner mistakes that I avoided in the initial overclocked build last year as I read a tutorial and followed it carefully. This time I forgot things like turning off SVID and other settings when manually setting the voltage. So I went from having an unstable PC due to power and an overclock that now longer worked reliably, why I do not know, to a poorly applied overclock that left the CPU unstable and exhibited the same symptoms. I've now got both adaptive and fixed vcore bios settings for various overclocks saved to a USB memory stick and stored on OneDrive. In both Asus's own format and as plain text files in case I have another bout of epic muppetry in the near future.
Alls well that ends well and I'm plenty happy with the card, and have now sold my Fury X and old PSU. All that said though given the time I've invested in fixing my own mistakes the thought of either paying Overclockers the extra to build my next major PC or a predone OC upgrade bundle is not only mightily appealing but possibly also economically sound (time==money etc.).