Hey Chance Ivey, thanks for the feedback. Unfortunately this means, it will still take a while, until this “gap” in UE4’s feature-set gets solved. I just hope, it goes fast.
To add more to my grief, i just found some spectacular video, showing of the capabilities of another engine on utilizing the DX11-Order-independent-transparency. Something like this in UE4 would blow my mind 
For everything in our business, glass and transparency is very important, thus i’m “pressing” so much on this issues. Anyway…thanks for listening into your dev-channels for me 
@Nicholas Eischeid: We didn’t prebake anything. In general i didn’t get very satisfying results from texture baking with V-Ray in 3ds Max. We tried this on some older project for another engine, but the results where quite a mess and it took a whole lot of work to establish a solid workflow for that. VRays GI calculation methods don’t really seem to play along nicely with the render to texture feature-set in 3ds max. If you want to go that way, have a look into mental ray, as it offers rather easy methods to achieve some fast and reliable baking-results.
For this project, we created the whole lighting in UE4, because we wanted to see, where we can go with Lightmass. We even have a prototype of this scene, that utilizes LPV-based Realtime GI. It doesn’t look to bad either, but the feature isn’t stable enough to go into production with it, so we wanted to give the “traditional” Lightmass approach a good try and it seems to get the job done