JayUtah
Penultimate Amazing
This is presumably the reason for wanting to split the discussion into "sub-issues" and "sub-sub-issues", etc. If he's arguing a "sub-issue" there's more chance of slipping his major conclusion into the premises without anyone noticing.
Yes, most fringe theorists want to drive deeper in to "sub-issues." In some cases, as you note, it's to disguise flaws in their reasoning. David Percy, for example, couches his Moon hoax claims into a 4-hour video and a 500-page book ostensibly so that you don't immediately see the many ways he contradicts himself through his presentation. The book especially is padded with irrelevant references to New Age concepts.
In other cases they simply want to drive the discussion into territory that, for want of a clear landscape of evidence, cannot be resolved either way. Keep in mind that most fringe theorists don't want to resolve a claim. They want it to persist for as long as possible because only then are they the center of attention. Keeping a discussion wallowing in insignificant detail or meta-debate is a common tactic to achieve that.