Bulging of semi-flat surfaces

[Scatterplot]

I needed to print a part with a semi-large flat surface. I'm using a LittleRP with Makerjuice SF for LittleRP (this doesn't have tilt if you're not familiar with the model). I tilted the part about 10-20 degrees and applied a lot of support columns, however, when it printed that surface was very deformed. The deformation worked itself out over the rest of the part, but that one flat surface appears to have bulged outward somewhat and is far too thick.

Here are a couple of pictures:



The top part is angled; it should be about the height of that right hand side, and should be flat. The angle is roughly the same angle that the part was tilting. This is a bottom-up printer and the warping was in the area that printed first (so the side closest to the build plate).



Here's the other side. The top area should be flat- the left side in that pic is the right height, but the rest of it looks like it's way too thick. The white scratches are from me cutting away some poorly-placed supports, which were my own fault so ignore that.

Is this something that requires a tilt function to print, or do I have some exposure issues or something? I've had this happen once before when I had a whole model suspended by supports (rather than being securely mounted to the base). Should I be forming supports a different way? I did a basic 75% density support grid in the B9 creator software as I was thinking "more is better" with a thicker part like this and no peel function.