I still think that overstates the case. "Tressaurian" was not made in people's homes and garages. The primary shoot was on a stage at a studio: Hell, there's even a crane shot. The things happening at home is the same stuff that typically happens on other fan films at homes or home offices: post production, like editing and VFX. And let's remember that this was filmed FIVE YEARS ago, and even Phase II/NV wasn't then what it is now.
I'm not sure who you mean by "They also have a big advantage in resources, particularly in the FX department having have NEO to do their CG work."
It sounds like you mean Phase II, but that's confusing because NEO f/x is doing work for Exeter
in addition to other fan productions, as has been discussed before.
My point remains that the main reasons for the time it's taken for this to be completed lay primarily at the feet of the producer, who made the post-production decisions he made for the reasons he made them. He wants it finished a particular way, even when there may have been other ways to complete it.