Fast travel should be restricted to smaller ships.

Ok hear me out here, small and medium ships can travel through the fast travel network but larger ships need some sort of warp drive. To me this makes complete sense to me because if you think about the fast travel as having a power draw how much power can Vallation station produce. Technically speaking the ability to teleport any size ship should come with a massive power draw and what, do the stations produce infinite energy. I think this is a bit ridicules at the current moment because you can take a ship of any size and just teleport it with no drawbacks.

Small Ships

For this to work id just base it off of the dimensions of the ship and leave mass out of the equation. small ships should have no problem being sent to other sectors, same with medium. A gateway device should take some power and then send them on there way. You should have to position your ship and fly through the gateway device for it to work. First you make a request in the map menu then you fly through a portal generated by the gateway device.

Large Ships

With large ships there should be an upper limit on the size that can enter the generated portal. Large ships should be required to have a warp drive or FTL in order to get from place to place. Otherwise you'll just have a person move a base ship or capital ship from sector to sector with no downsides and no reason to build Stations at location. Something like the Super Cruise from Elite Dangerous would be awesome. I do think that small ships should have access to the warp drive to but large ships would be the ones that need it the most.

sorry if it seems like I'm talking out my rear but I feel this would add a good balance to the game. This also ties into another post I made before this one. https://support.keenswh.com/spaceengineers2/pc/topic/53932-you-should-have-to-fixrebuild-parts-of-vallation-station-before-fast-travel

Anyways happy engineering.