Diagnostics, EGR and low boost

My Octavia VRS TDI DSG has had an existing intermittent fault with fuel pressure and boost in past and also plug 3 misfire when under warranty. Anyway it went into limp mode yesterday on M1 40 miles in - first the Eng Man light illuminated and then limp mode activated then after 5 mins the coil light flashed and I pulled off at jn. 29. I switched off car to maybe help reset after cool down. It didn't so got AA out to recover us. Long and short the following faults came up on the tablet.

P190E00 coolant pump charge air cooler /power supply static fault

P029900 boost pressure control below control limit.

Spoke to DM Keith and they want to charge me £90 to plug in.

Spoke to VWAG indy with same VAG diag. kit he will do ot for free.

My question will DM Keith ignore the readings if its captured using the same kit?

The VWAG specialist has a suspicion this is a knackered EGR valve and will cost £350 for part and £450 labour.

If I go to DM Keith they will look at trying to get Skoda UK to fund some of the cost but can't promise anything.

Has anybody been in a similar dilemma? And what the outcome given past issues?

TIA