I don’t have 4GB DDR4 sticks to test with. Buying memory new, the savings of 2x4GB sticks over 2x8GB are so low I wouldn’t bother. Single channel memory tends to hit performance hard (especially with APUs). Store-bought PCs with 8GB are often single channel, leading you to buy another stick anyway.
A GT1030 is attainable but new it’s at least $100 right now. If you have to buy a CPU as well, the cost of any CPU + GT1030 vs a Ryzen 5600G may be a wash. I kind of feel the APU is a better value if the computer / parts will ever be used beyond Zwift duty. If going prebuilt, it seems a lot harder to find a computer including a GT1030 than one with a 5600G. I was thinking in the context of buying new, but certainly if you’re augmenting a computer you already have (or a cheap recycled business box) with a $100 card it’s cheaper than building a new Ryzen APU system from scratch.
I’d also heard bad things about AMD drivers and OpenGL but at least in my test it wasn’t an issue.
I want to grumble more about Zwift’s graphics configurability and needing to wait for them to test modern hardware but it’s beating a dead horse.