Okay, it seems that all I've learnt will be viable only partially. Wan 2.2 is an interesting fruit, that's for sure. BUT, it seems that frame interpolation I was dreaming about, alongside the upscale, are finally here. (First one is just interpolated frames and different seed, second one is just my first attempt). 1 and 3 aren't posted above here, so check them out.
I'll upload more anims as MP4s because quite frankly the GIF quality seems dissapointing. 33333 is both upscaled and interpolated, but as you can see I lack general movement, which I hope to fix within the next few days - or maybe a day.