That one i can answer (as not being dev)
I know that the devs use 3DS to model their... models.
Hero engine behaves like UDK where this is concerned.
So the standard export, scripting etc will behave the same for modeling animations and exports.
Hero Engine provides scripting for 3DS and several other modeling apps for easier transfers.
I am more familiar with Hexagon than 3DS, but thanks to standard Export design I transfer anything I build into 3DS, and export to game desired platform.
I hope this answer your questions.
To add: time wise it does mean that they have to re-export everything into Hero Engines desired format as previously all work had been done for Multiverse (ogre)... time consuming