You do not explicitly mention TSC, 'through spindle coolant" but most times when high pressure coolant is used it is TSC.
TSC requires rotating seals and if the system pressure is low these can be fairly simple and there are no fine passages to block. However, with a high pressure system the rotating seals could be labyrinth seals; I have no idea if that is what Doosan Daewoo uses but if they do these seals are sensitive to small particle contamination. Labyrinth seals have fine working clearance and the rotating parts do not actually make contact. Instead they allow a small leakage through a tortuous path (labyrinth) which keeps the seal cool. If the clearances in the labyrinth get clogged with particles too large to pass through you could have serious problems.
An open mind is a virtue...so long as all the common sense has not leaked out.