Jig and project files are typically hosted by their individual authors/designers for anything that could be considered a taxable manufacturing activity.
A Trump-era rule classifying these files as Defense Trade Articles prevented openly sharing online (at the risk of sharing the information with someone not located in the US, a violation of the AECA).
For the past three years the repositories for these files have pretty regularly been pulled down by ISP's and hosting platforms and their creators banned from those platforms. As a result, there are a lot of different working versions of the jigs and projects out there.
This rule and the Department of State overseeing it were defeated in court a month ago and some sources are starting to more openly share files again. Individual states are still filing nuisance lawsuits and injunctions against content creators though, so most folks are still sharing in an 'all in one package' format, with the links shared in semi-private community spaces. There are GG discord and IRC channels, private subreddit's and forums, and random file dumps on related sites; just takes a little searching to find specific project files. If looking for GG-specific files, the .dd file extension can be a helpful query within community forums and chats... people also tend to be more than happy to share copies of files directly peer to peer, though there's some risk of malware to be aware of if the person sharing with you isn't a known entity in the community...
The FOSSCAD repo I've previously mentioned has around a dozen different jigs in the package; most are intended for manual operation with a drill or hand router, but can be adapted to mount to the FLEX table. Some are specific to the GG and contain .dd files already. Pulling dimensions from the CAD files therein is also a big help, and some parts don't even really need a jig/can be bolted straight to the GG's table.
(The FLEX project itself doesn't currently host any of these projects/jigs/files, nor do we promote any particular activity involving the FLEX over any other for legal reasons. We are in cooperation with another group of designers in the space trying to set up a third party hosting platform/repo intended to function similar to Thingiverse, but have a ways to go due to a lack of manpower and limited finances at the moment.)