The remap day has been changed to the 11th at Area 52 as the weather was getting worse and didnt want to map it on the road.
Ok so from what it sounds like you have a boost leak, that much is obvs, get some carb spray and spray it onto all the pipes on the turbo circuit, intercooler etc, what the carburetor spray will do is make the revs go up if a leak is found.
Other than that i can only think that you have a DumpValve that is sticking open which is causing the drop in boost before it should. If you have a dump valve get some WD40 and spray it into the DV, leave it for a few mins and then rev the car, once warm obvs.
If failing that im sure Martin will have a look at it either before the meet or on the meet.
Well you will be able to try some of Gems world class baking :)