I kind of figured there wasn't anything on the RoboHelp side. I'm going to check with a few developers to see if there is anything on their end that can be done.
I found this reference in the RH7 help which seems to imply you need to compile Section 508 compliant help? I could be barking up the wrong tree though, as I haven't done any work with accessibility requirements.
Yes, I've seen this content----and WebHelp is complied.