Has anyone tried making a mod that adds Waygates from the Gamesjam video?

There are some mods that do the Frostcrag-style teleportation systems for player homes, but I'm not certain anyone's done a straight Waygate system mod like in the Game Jam video. I don't think it would be overly difficult to do, though. The most difficult parts would be figuring out the best places to put them and setting up the markers, message boxes and scripts behind them, as well as setting up some kind of a quest to activate them, the latter of which only being necessary if it's more "ideal" for those that want them to be implemented in a more "immersive" way.

At minimum, all that's needed is a base Activator object for the Waygates, markers to send players and companions (followers, horses, etc) to, message boxes for location selection, and the scripts behind the boxes that actually send players places. Simple Door objects can work for Waygates as well, though that would mean having multiple Waygates per location and maybe the use of shrines with interior cells to maintain the location distinction for the Waygates as well as more space to actually fit the Waygates into, but that's doable as well, though it might be more limiting.

That is encouraging, I may try this myself then. I am not a fan of using the map for fast travel so I was wanting a system like Morrowind's Propylon chambers. I could make a simple quest that would require to find the keys to power them on too.

What the Game Jam did became what Dawnguard uses for the wayshrines quest. So if you've got Dawnguard, you can pretty much see how it turned out.