Some colleagues in my fleet asked about jumping ship from fast jets to one of the ME fleets recently; very open about it, happy to go through 45(R) and take anything they were selected for rather than a specific fleet or anything. They were told the door was very firmly closed, but I don't know if that's because they needed them to stay in the FJ world or if the ME world was full to bursting.
Good luck regardless; do ask the question!! If you want to build some FW hours of some variety, have you considered trying to get yourself to CFS to teach on the Tucano or Tutor? Not an A330, but still non-rotary hours, and probably a nice change away from the stuff that's starting to make RW life a grind.