WordPress 5.3 will have a new default core theme: Twenty Twenty. We need to make sure that it works as well as possible in AMP.

Note that Twenty Nineteen support (#1587) did not have 100% feature parity in AMP specifically due to the navigation+ menu on desktop and the sidebar menu on mobile. Ideally we'd be able to achieve complete parity. Note that this may involve submitting patches to Twenty Twenty itself to reduce dependence on JavaScript for implementing the desired functionality.