Printing Large Flat Piece - getting waves and other issues - possible solution?  

Printing Large Flat Piece - getting waves and other issues - possible solution?

I'm dealing with a hexagon that's 200mm diameter (corner to corner), and 10mm thick. No features, just a flat tile.

In the past I had problems with waves and ripples and got help here and putting down glue on the print bed solved the problem.

The problem was, as I understand it, issues with tension over the large flat surfaces, one on the bottom, adhering to the bed, and the one on top. I'm wondering if the problems would be reduced or go away if I just added some kind of ribbing to the top - not a lot, but something like what I did for support on a smaller piece:

My reasons are mainly convenience and to save my own time (and maybe laziness?). I do most of my design work in my study/office, in the house, and there are times I can't make a trip to the shop just to put glue down on the print bed, then go back to the house.

I've just wondered if adding this, or maybe doing a reverse and adding some creases instead of ribs might make a difference in printing these tiles without ripples on the top surface without using glue. I'm also open to other tricks that might work.

I don't mind experimenting, but figure if someone here knows about this kind of thing, it might save me from going in the wrong direction.