I’m really not sure what you mean. But if you want to provide two versions, You can make a private repo on github with two branches: Dev and Release.
I don’t think Envato would be interested in providing two versions of themes.
Also, if you do not want to provide support to an item, you can mark individual items as not supported.
There will always be customers like that. Best way to handle them is just help them and explain what is and is not included in support… point them to the support policy doc in Envato.
We’ve had a customer before that threatened a 3x 1-star rating across multiple accounts. Nothing could be done except provide the support we normally give.
IMO, it has nothing to do with using multiple versions… just help them by finding a workaround that can make your product more compatible with even more 3rd party products.