For the record, XDA is a fantastic forum, especially for anything generic Android-related. However specific CDMA-based handsets have never been all that popular over there (with a few notable exceptions, such as the HTC EVO).
For example, back in the days of Windows Mobile, the Touch Pro 2 GSM version had quite a following on XDA. However, there was almost nothing for serious ROM development of the CDMA Sprint/Verizon version.
In fact, when folks asked for a section on XDA, the response was usually something like "there isn't enough interest in that handset for its own section". Almost everything was happening on PPCGeeks.com, and once the community was established elsewhere, eventually an XDA section was born, with stickies and FAQs pointing to PPCGeeks.com mostly.
Same was true of the Optimus S. Almost all Optimus developments were happening for the Sprint network on Androidcentral.com, AND NOT XDA.
For my nearly 10 years of posting there, I can say that XDA appears to cater to a global market, which is mostly European-band GSM phones, and the smaller CDMA markets (boost especially) hardly ever get any love. Androidforums.com seems to be were most of the Boost support comes from, and Androidcentral.com seems to be preferred for a lot of the smaller Sprint options.
For Sprint, androidcentral.com has had a pretty decent section of their forum for the marquee, hosting many early conversations between myself and tcaudill01 (arguably the person who got the closest to actually cracking this thing open). The conversation there eventually died out when there wasn't enough interest, and only came here recently when it launched on Boost months later.
As far as getting O-Black people to help... Tcaudill01, myself, and a few others have tried to illicit the help of folks from XDA. If you search the Optimus Black section of the forum there, you'll find a few posts dealing with the Maruqee, and you'll also notice that they are not met with much fanfare. I wish I had better things to say right now, but until we get a Marquee into the hands of someone who knows enough about recovery to figure it out, jumping to another forum isn't going to solve anything.
I had a marquee for about 2 weeks. I'd love to see it cracked open so I can adopt it again, but sadly I don't have the time or skill level for it myself. I've tried conversing about this on every Android forum I could find, even down to harassing known devs on twitter.
My hope is that some of the Boost devs (I know there are quite a few budget conscious brilliant minds out there) will eventually adopt this handset and shine some light on it. But I have a feeling it won't happen on XDA. My 2 cents.