From 3ds max to unreal...and BACK

Hey there,
just started out playing with unreal, as I wanan move my shortfilm from 3ds max to unreal for shading/lighting and rendering.

I´ve successfully exported an existing archviz scene via datasmith from 3ds max to unreal.
But now i´m wondering if its possibly to go the other way around.

The idea here is: While I might set up some scenes in 3ds max, I might also use unreal for environment layout.
But lets say I either need to simulate additional FX in max or realize I need to render some stuff in 3ds max because of polygon or shader limits…
Is there also way back from unreal to 3dsmax?
Is it as simple as just exporting the whole scene via FBX, or can I use datasmith for that as well?