I trust there's a big misunderstanding here: from the first day anyone was able to import externally made avatars, as long as they were built to adhere to a list of technical specs, so you have FULL creative freedom :)

The customization sliders in the program are just there for folks who do not want to put in the needed work to create their vision from the ground up, but they just want to pull on some sliders :).

Here is the Steam forum section for user-made 3d creations :
http://psteamcommunity.yuanyoumao.com/app/274920/discussions/6/
( Documentation, samples and whatnot) .
You can build your avatars in what 3d program you know best, provided it can export to Collada.

Here is the Steam forum section for user-made 2d avatars , with Live2D (recently launched, you'll need the Live2D module for FaceRig)
http://psteamcommunity.yuanyoumao.com/app/274920/discussions/8/
( Documentation, samples, tutorials etc)
You can draw it in any program of your choice, provided it can interface with Live2D.
We recommend programs that can export to PSD format (Photoshop, Clip Studio Paint), but there are also ways around that.

You can even try and edit the Live2d textures directly if you want more customization, but you don't really want to build an avatar from scratch or to install the Live2D Cubism editor.


On a side note: It makes no sense, financial or otherwise for the Holotech Studios team to start building a 3d modelling program, as long as there are so many excellent ones already out there that folks already know how to use, with tens ( if not hundreds) of millions of dollars put in their research and development , (some of them even absolutely free such as Blender3D.). They have tons of documentations and excellent tutorials .
We want to focus on offering something that's missing, or not well enough represented.

Ah, well, first off, I feel like I've insulte you slightly. I want to apologize for that, and for making assumptions despite my ignorance towards the subject. I also barely understood what you said, so I feel extra stupid now. Sorry!