I hope to get good use out of this table with my Thousand Sons. Easy to make and easy to store. The portal shenanigans makes up for lack of terrain at ground level when playing here at home with friends.
When used for
40k, you can enter a portal with a single infantry unit each turn as if it is a vehicle, but you must disembark next turn. When doing so, you can exit any portal you like but the penalty is that one model of your choice suffers Perils of the Warp. If you just want to travel without suffering Perils, roll a d3 when you want to exit and that will be the portal you must disembark from. If you can't place all the models in a unit when you disembark, you have to stay in the portal.
The stands and floating island bases are completely ignored during play and don't provide cover. Jump infantry and jetbikes may fly up onto the islands. Only vehicles with front
AV 10 can get on the islands.
FMCs can get up there unless they are Gargantuan. If you shoot up at infantry models on the islands while on ground level, they get a 5+ cover save.