I'm thinking further: The Brexiteers will perhaps cry foul over Bercow when he goes to the EU to ask an extension himself, but perhaps Johnson in some way doesn't entirely mind that arrangement seeing as he rather had died in a ditch than doing that himself, and to be fair if asking for that extension is so much politcal pain perhaps it's best done by one who is soon to resign. As it stands with the Benn act, afaik some representative of parliament will have to ask for an extension in the case of no deal because if the UK goes out on a no deal technicly parliament as a whole would be culpable for it trough inaction?
Bercow then would have a mandate of parliament, not nessecarily be the representative of goverment, as if the speaker would be a natural representative of parliament*? Because, while the Benn act does stipulate by law that a no deal brexit is illegal, it doesn't really explain to who'm it is to go to the EU to ask an extension above the head of goverment when the PM wouldn't be up for it?
*I guess he must be since noone was appointed in particular, kinda cool that it goes into international matters aswell. I mean, it's a bit like Having Nancy Pelosi visiting Britain to rectify some illegal deals of Trump.