The problem with putting the shut off valve between the UAT and the pump is that the valve can act as a restriction which the pump must overcome when the turbine is running in normal operation. The restriction can lead to cavitation and bubbles being created in the fuel line to the turbine. The small Tetra valve provided with JetCat engines certainly is a restriction, but it is installed on the 4mm output side of the pump. A 6mm Festo 1/4 turn ball valve provides little restriction and can be installed on the inlet (suction) side of the pump. However, make sure that the Festo seals properly as any leaks will result in air being drawn into the suction line to the pump.

If I had to shut down the turbine due to a fire, I would do it using the transmitter shutoff (closes both the fuel solonoids and kills power to the ECU) rather than reaching into a plane that is on fire and I may or may not be able to see the flame in/around the shutoff valve. Of course, but this time I've already given it a shot from the extinguisher.