I've been testing Affinity Designer's SVG export and it's not impossible to get by. So far I've learned that you can't use layer blending modes, and groups of objects as mask. It also has trouble exporting color gradients correctly if the object they're used on has also been transformed.
I'm using Affinity Designer's isometric features for the first time and they're so good, holy shit. Unfortunately not useful for the things I typically draw, but for my current project I would've gone insane without them
Volpeon