[ORD] Cross sections to even heights?

This may be something I'll have to live with, but I'm going to need your help explaining it to my PMs.

I see when I place my named boundaries, I have the option to define the "envelope" around my section - min. distance above and below the actual section linework. This does indeed give me a buffer of (say) 5' above the highest elevation in the section. But it's literally 5' above the highest elevation, whatever that may be.

The bottom elevation of the grid appears to be set to an even 5' increment, like 735. But the top of the grid is not at an even 5' increment it's not even at an even 1' increment. I have two consecutive sections, one of which has grid to 752.07, and another to 751.70. Why...???

Like, no, I get the logic of what is happening. But it looks bad (to me) and my engineers are VERY used to seeing grids to even 5' increments. Preferably the same size when possible. This "whatever" elevation is likely to cause consternation and complaints. So I'd like to find some way around it if I can! If a cross section can fit between 735 and 752.47, it can certainly fit on a grid from 735 to 755. This is what we are all used to seeing, and this is what I would like to create.

Is there any known way to create a rounded ceiling instead of a hard envelope for generating cross section boundaries/drawings? Is there any way to edit the height of the named boundaries after placement, to force them to an "even height"?