The Flatpak is already packaged and works well. It just needs to be maintained from a person that joins the Inkscape community.
This would allow further improvements like Portal support and making the app official on Flathub.
Update: One might have been found!
*'til
But the lack of verification and validation is a huge risk to flatpaks. As someone formerly involved with securing OSes, this kind of thing was scary back then and doubly scary since it entered its “don’t confirm; just get in, loser” phase.