Matt

Turbines are not as fussy about direct smooth air as EDF. The EDF inlets are bigger than needed on a turbine aircraft, so cutting them off and sticking a tank in front is not going to cause you a problem. Tail pipe set up to draw out the hot air and gasses is more critical, turbines don't like breathing hot air, so partly blocking the inlets is probably good.
I've only seen one Preceptor fly and it looked heavily loaded even on 6s EDF. The std legs are chocolate aluminium as they bent easily on a landing which got a little bouncy. Mt CARF Spark with a P-60 and 1.8 ltrs did 7 minutes blasting it around. Start with the timer at 5 1/2 minutes and see how you are after a couple of flights, not using full power (at all) makes a big difference to fuel useage

Dave