if it is jerking from 2500 to 3800rpm, I would say that is when the load or boost is at its strongest, just after the initial spool up
I would hazrd a guess that the turbo intake pipe is collapsing. The only way to see this might be on a RR and getting the tuner i.e. Awesome in this case to have a look and see if it does this
common
problem on the Leons with the pipe collapsing. Once it gets quite old it becomes weaker and as you are mapped, this will almost certianly show up this issue with the extra pressue being put onto this pipe
I know it's becoming a money pit, but get Awesome to check this first, and if it is, then you will need something like the Forge TIP, which is about £120
but thats a cheap price to pay in order to resolve your issue mate
if that is the
problem, then I can't imagine the issue to be the coils now. although certianly replacing them will smooth out any jerkyness anyway like it did with mine
let us know how you get on at Awesome on Wed