I experienced a similar situation on a previous map - crusing on motorway in 6th, went to boot it and nothing happened. No warning light or fault codes. After approx 10-15 seconds of rolling, the boost would return.
This happened a few times, but only on motorway and only under full load at approx 3k rpm.
Went to a JKM rollling road day, and had a graph that looked like a rollercoaster - up nicely to 3k, then dropped slightly and then continued up to the redline. Peak power, it actually made more than a Revo stage 1 car on the day, but mid-range (mid-dip) i was down approx 35bhp.
JKM looked at the car, and the map was requesting more fuel than the HPFP could deliver, causing fuel cuts, but oddly with no faults logged. I changed maps and now also run an APR HPFP & all is good.
I am not stating or implying that your R-tech map is causing your problem, but in my case, my fuel pump was weak & couldn't meet the demand of the map (which was not an R-tech map). I'd speak to Nick when you're up there this week.
Do you know when your cam follower was last changed? if not, as others have stated, it could be an idea to change it.