Would it be worth approaching ASIFA-Hollywood about potentially sponsoring the Natron development? They have supported various software in the past, such as Audacity, GIMP, Inkscape and Synfig. Synfig posted about this in June 2018 and revealed that they got $2000 from them, which is certainly not enough for full time development but it’s definitely a good thing.
I don’t yet know if they support individual developers or if you/Natron has to be a registered company.
Would this be something worth approaching them about? I have experience in applying for funding, although this is mainly for visual arts in the UK. Regardless, I’m certainly willing to take the lead on writing to them.