Hooray! You've tucked accessibility into your backlog like some problem for future-you to solve. Strategically right between "refactor CSS" and "update the docs."
But that's not a strategy at all. You know it's never going to happen.
You're just taking on more technical debt with every release without proper semantics and keyboard support. I've never heard of users with disabilities politely thinking to themselves, "oh, this thing I need that won't let me go on is scheduled for phase 2, let me wait it out."
If you prioritise features that look good on pitch decks and demos under perfectly controlled conditions, you're not doing yourself any favours.
I really do get an itch when I hear "we'll address it in the next version." Roadmaps are for features. And accessibility is not a feature.
Ship it properly from the start or admit you're okay with locking people out.