Since "BootCamp to XP" is part of the process now could Premiere on a PC with XP be used to edit the Quicktime reference file and send the EDL to scratch. Seems like being all PC based if you're using scratch would be a better solution right now for people who can go either way. Does this sound accurate?
I'm not Lucas, but as a reasonably long term Scratch user, I can supply an answer based on experience. Scratch is a Windows program. To get the most out of it, and certainly to use it in a professional environment (to my mind, the only way it's meant to be used) it should be run on a Windows box, preferably a rather high end Windows box, with full access to all peripherals and file systems it expects to see. That includes NVidia SDI cards, Bluefish and Aja video I/O cards, NTFS file systems on the system drive and on other drives as well, available multilane expansion slots (you're going to use them up completely in an Intel Mac simply by putting in the Aja and NVideo cards - and you can't put in the SDI card at all) and in general, full Windows compatibility, both hardware and software. Running Windows on an Intel Mac might be possible (indeed it is, and it runs well), but the hardware restrictions on the Apple side make it a dubious choice for a program like Scratch, which is really meant to be used with fairly specific hardware - especially in terms of the video card - that Apple doesn't happen to support. I'll repeat my oft-stated mantra: Just because you can do something doesn't mean you should. Especially in this case.