There is a company, not naming any names, but its a big well known one that does pressure style chips, they apparently instal a device which removes the safety pressure valve on the common rail in the D40, now Denso specifies the rail can operate at and up to 2200BAR in the nissan YD25 service manual. My issue is changing this you essentially turn the fuel rail into a bomb, any poor welds or fissure cracks could cause it to explode/fail catastrophically, it'd be like removing the pressure valve in a hot water system, very dangerous and IMO pretty stupid.
Apparently the pressure chips cause more issues with the hilux 1KD than anything else though.
in any case I voted exhaust-chip-IC since you have an intercooler.