Proper vacuum bag setup w/ breather mesh?

I use a grooved MDF panel on the bottom. Then wax paper where there might be glue squeeze. (Don't want anything sticking to the forms.) Veneered panel face up. Then a thin flexible door skin with mesh. I use a vacuum bag that already has the adapter for the vacuum hose connection. You can use another ungrooved platen on top of the mesh. However, it is not normally required. If you use a top platen make sure it is only 1/8" oversize of the shape so as not to have the vacuum bag put too much pressure on the perimeter. Too much overhang can cause the center to try to bow up thus putting less pressure in the middle. Or actually break the top platen from extreme pressures on the edges.

Welp, I went ahead and did what I thought made the most sense, and I got SPECTACULAR results. Flattest, most bubble-free panels I've ever taken out of the bag. Here's the proper set up:

1. Un-grooved platen
2. Panel, show-side down
3. breather mesh overhanging panel on all sides
4. close bag and turn on vacuum

We flattened the veneer with J-rollers as the bag tightened, but for the most part it wasnt necessary. The breather mesh really takes care of flattening everything.

I am going to do veneering for the first time for my current project and there will be a quite a bit of veneering. Since i have no experience with it, I am curious about one thing you mentioned: How does the breather mesh flatten out the veneer if the veneer face is down? Does it do it by evenly distributing the pressure?