Bwitesox,
I think Tourby said that the dish has to be shallow to accommodate the spring mechanism so I doubt there will be enough material there to make it .8mm recess. But I'm sure he will comment on this much better than I can.
I just wish there was a way to use the same manufacturing process that was used to create the spring loaded crown with less polishing on the classic deep T48 without spring. I know Tourby created this because people were always complaining about how deep his crowns were but I personally bough all of my T48's precisely because of deep dish. Myself and many others with OEM, Jimmy, Little Hero, SNembo, Torobravo and old cartel crownguards will have to get Palp's deep dish crowns.