To take advantage of your intercooler you would want to increase your fuel. But it does increase cumbustion pressure. Water meth would be a much more effective way of cooling EGT's. More so than an intercooler. The Intercooler is used to get more air into the cylinder for more fuel. It is not going to radically reduce the temp because the air ends up compressed in the cylinder causing extreme heat build up (EGT's). That is why the use of an intercooler on a pre cup engine is not widely used.
At 15psi with a 20 degree C intake, the air leaving your turbo is just over 100 degrees C.
A good intercooler can strip this down to about 40 degrees C, a great intercooler can get it even closer to ambient.
This drops your EGT's by a similar amount, reduces cooling load on the engine and increases engine efficiency.
Plenty of factory turbo intercooled IDI diesels around. Mitsubishi, Mazda, Toyota, Isuzu.
Of course IDI is old technology, all modern performance diesels are direct injection (this includes common rail and unit injectors).
The 13BT being discussed is direct injection.