yes osKitchen 1.25
works, but you have to modify two things:
1. edit \Resources\Tools\htcrt_devices.ini: (it seems to me that MEGA has to be upper case)
RomSections=4, "0x200,SPL,524288,TRUE", "0x600,Splash,655360,FALSE", "0x301,Radio,23199744,TRUE", "0x400,OS,0,FALSE"
2. AFTER cooking first rom with these settings, DON'T flash it yet, you find a file ferom.htcrtproj in the \flash folder.
here change this line:
now cook once again and you can flash the rom to mega with custom rom tool that comes with hspl
i cooked with the sources from: