I'm running a D4 and don't know if I can make that mod. I ordered a 2nd D4 which should be arriving today, so maybe I'll take it apart and see if that mod can be performed on the D4 as well.
As far as leaking, I don't think that's as much of a concern as the pump not spinning since a leak under pressure is likely to blow up your system anyway since the water would pretty much go everywhere. The problem with a leak not being able to shut down your system would therefore be solved.
