I feel for "Family Emergencies", and I hope all is well.
Also, thinking about how this started from a Kickstarter, could you run another Kickstarter for Spriter 2 to bring on some other coders to finish the project faster. Or, have a Patreon for short term goals like this plug-in in order to bring on other programmers? I applaud your efforts at not charging people more money for a product they have already bought, but I believe there are some people, like me, that would pay to support the product's development (as seen in some comments over the years).
I'm an artist, so buying SpritePro packs doesn't really hold value for me, but if said that X % of money is going towards the development of Spriter Pro along with community surveys to which feature people would be giving money to develop, I would buy more SprierPro packs, and I think you could raise money for certain features as well as bring others for short term help.
I digress as I don't know all the stuff that's going on in the background and my view is coming only from my perspective, I just wanted to share my thoughts.
Cheers