Fusion 360 creating curvature on seemingly flat faces, causes scene to be extremely heavy and slow. Can faces be flattened?

[epoliqui]

I've been trying to cleanup a STL that was about 1000 tris. The process has been absolutely excruciating. 

My newest issue is that on completely flat faces, fusion will create curvature that's pretty much completely hidden until I go into the curvature analysis.

Can these faces be flattened, or can you delete curvature somehow? I've been working on this for days and I cant really find a solution that doesn't involve me restarting the whole thing. 

[TheCADWhisperer]

No history?

No mesh?

It shouldn't take long to remodel from scratch (with Capture Design History turned on).