Well, the GeForce GT 730 works like a charm with the upgraded 90 watt power adapter/“supply”, so seemingly don’t need to do the significant downgrade down to the 710. It’s a rather massive upgrade in graphics performance compared to the integrated Radeon HD 8400 (probably thanks to the fact that I got the 2GB GDDR5 version) to the point my CPU might be holding it back. Pretty sure this is close to the pinnacle I can get for this desktop that the motherboard can support.
I would type this in the happy vent thread but there’s another, tangentially-related issue.