As for Ertai himself as commander, he's enough of a control deck you don't need to flicker with stuff like Deadeye Navigator

Unlikely.
There is a bizarre line in Sisay cedh decks that get infinite mana and flicker ertai infinitely with Emiel the blessed flicker for a lock.

But at that point you just counter the emiel flicks and draw your deck for a win.

Thank you for the time and the nice token. I drew the planeswalker the best, I just have the worst audience

Was not expecting that much prowess