I don't think extending the runway is that far up the list of priorities. A330s regular to SFB and POP, 757s this year to Toronto and Hamilton, TOM and EK launching long haul routes are fully aware of the runway length, it's not a problem. The aircraft calling into MME was MYT's Airbus, but that's now ended after they changed their SOPs. Realistically what will a runway extension give the airport that they cant already do, other than a fully loaded 747 to Asia, which wont happen anyway?