Migrating to Mithril 2.x routing: how should focus and screen reader announcements be handled after m.route.set?

Context

We are migrating a single-page app from Mithril 1.x to 2.x. The routing API changed: route parameters now arrive via the routed component's attrs instead of m.route.param(), and navigation goes through m.route.set(path). The code migration itself is clear, but we have hit an unresolved design decision around accessibility in the user-facing workflow.

The unresolved decision

Client-side navigation with m.route.set triggers a redraw and swaps the routed view, but nothing moves keyboard focus or announces the page change to assistive technology. Sighted users see the new view; screen reader users apparently stay on whatever element had focus before, which may no longer exist in the DOM.

We are considering wrapping routed content in a <main> landmark and using the routed component's oncreate hook to move focus to a top-level heading on each navigation. What is unclear is whether this should live in every routed component, in a shared layout component, or in a route-change hook, and how it interacts with Mithril's auto-redraw timing.

Questions

• Where is the most reliable place in the Mithril 2.x lifecycle to move focus after m.route.set so it works for every route without duplicating code?
• Should focus go to a heading, the <main> landmark (with tabindex="-1"), or should we rely on an aria-live announcement instead?
• Does changing m.route.prefix during the same migration affect any of this, or is it purely a URL/server concern?