It's all caused by this line which isn't directly delegating to m.route.set, but is instead using an internal call skipping the reset logic.

It's not causing any apparent bugs, just taking up more space than necessary. The relevant variable set, lastUpdate could probably just be made a simple object token, so the closure isn't itself being directly persisted.

I've conservatively marked it as a bug, in case there is actual observably buggy behavior here.