BOV on a diesel is not hard to do. just need to change the spring, rig up some vac solenoids and micro-switch on accelerator and clutch.
ZD30 has an intake butterfly and same with some versions of the YD25.
BOV is not bad for a diesel, just very limited gains to be had with a stock engine.
the boost in the intake does not keep the turbo spooling, it slows it down as it tries to go back through the turbo, which no longer has drive on it due to the lack of fuel. also boost is not required by the engine as there is minimal fuel going in.
unless you cannot get rid of the intake butterfly, i wouldn't bother with a BOV. to expensive for very little gain.