When will supporter pack upgrades be available?

Greetings,

I know that it has been talked about before regarding the supporter packs being upgradeable and that GGG is looking into adding support for it in the near future, however, since then there have been a few patches and no updates regarding this feature.

So my question is if there is an update on the progress of this feature and if GGG thinks they will be able to have it out before the end of the Harbinger league. I can say personally I would be willing to upgrade my portent supporter pack to a harbinger supporter pack but I do not have the extra money to spend on a $60 harbinger pack by itself. I'm hoping GGG can add support for this before the end of the current league as I myself and presumably others are waiting and hoping to be able to upgrade.