But it still scales down nicely, I mean, the switch version is great. Why are japanese games so weird on pc?

The engine is kinda API-bound, you won't be getting good framerates at any resolution. I have an RTX 2080 Ti K|NGP|N overclocked to kingdom come, it's not good for much when CPU/GPU-synchronization prevents the GPU from working on more than one frame at a time.

The game doesnt enable them tho, and it doesnt seem to like the nvidia control panel forcing it. I wouldnt mind just downsampling but the game seems to scale badly upwards and it begins to drop frames even on a 2080ti at 4k :(

No, it's a deferred shading engine. You either supersample or use a post-process blur filter (i.e. FXAA or SMAA)

Can this make the game have AA without me having to downsample from 4k?