if i'm not mistaken isnt HRoid just a mod for VRoid studio? which means couldn't you technically allow people to upload and use their own VRoid characters in this? if so you should definitely think about adding a feature like this in the future. huge missed opportunity otherwise.
Viewing post in Project ARK : PROLOGUE comments
We have plan for Custom maids in the future. Players may create them with options to adjust height, face, curve, thickness and so on. Players can also make their own dress by editing base mesh in photo editor program (See maple story 2 for example).
It is definitely possible, to drag and drop V-roid model at run time but we will have issues with animations. That said, we will do contest periodically and select a winner to have their Model integrated to the game =).