Well last time we looked at Invisionboard there was not a way to pull thei header footer hense that is why you have never seen an enhanced integration after every version they have released. Likewise since they have a gallery product they have no interest in collaborating with us to support such a thing.
If you know a way to pull there header footer from there forum around a custom page feel free to post so I can comment. That is the only way we can support such an integration is if there is a way to pull out the header footer from the forum and show it elsewhere. I do not own an invisionboard license or have any access to there site so really this is not something I can comment on alot.