Let me preface the following statement by saying that I am not an expert (by any stretch of the imagination) on this subject. The only thing that I do have is my own individual results.
When I moved from using a 4" diameter mold to a 6" diameter mold, I did so with no increase of weight and my wheels turned out fine.
Yet when I moved from a 6" diameter mold to a 7.5" diameter mold (and especially the 8" diameter mold), I began to have a LOT of trouble.
Whereas before, my wheels would always knit together and come out very good, my first attempts at larger cheeses came out looking cracked and very rough from inferior knitting of the curd.
I honestly had no idea what was going on and only after asking for help on this board did I find out that higher pressures are required for larger diameter wheels.
At first I was skeptical (see my posts in the referenced discussion) but eventually came to accept that this information is correct.
I did eventually accept this information because:
1. I gave pressing at a higher weight a try and it worked (and has continued to work) perfectly.
2. I received information from Jim at New England Cheesemaking Supply, stating that this information is correct.
As far as being able to give scientific evidence of the validity of these claims, I am not able to do so.
I can, however say that it has worked for me, in my own cheesemaking.
Good luck to everyone no matter what method you choose to use.