I done the ME/IR first then moved onto the SE/CPL, I may be mistaken but can't you do the MEP test combined with the 170A doing the G/H part at the end? After you've done the IR side of things the VFR part is a doddle with a small part of IF work at the end of the test, I'd say doing the IR first also sharpens up your flying when you come to do the CPL.