110,000 miles

Hi ya guys,
Van suffers poor performance below 2500rpm.
It does carry a lot of weight. Owner is a plumber, it's LWB and it's loaded to the hilt....This is fact is playing on my mind. Once it gets going, it goes ok though!

No codes.
Compressions fine (quickie Pico relative test).
All intake hoses and pipes good. They've been off, cleaned and smoked independently.
EGR all good and working fine. Surprising how little carbon build up there was....

System is Bosch CP3.
Idle to WOT (see below) is 1.5 secs. I thought this to be sluggish. Anyone care to comment on that?
1st image is MAF vs Rail pressure.
2nd is rail pressure on its own.

Thanks very much for any input,
Andy