What is going on?

["Lurker"77]

If someone wants filler conversation, help me out on this:

With MLB adopting a no-pitch walk rule (as other lower-level leagues apparently already have; I have not found text available) and the recent post on BOO . . .

Baker is the scheduled batter. However, Carl is in the on-deck circle and approaching the plate. Without the walk rule, the defense has to pitch to Carl and wait for him to reach base in order to appeal and have Baker declared out (yes?). Until that happens, Baker can correct his error at any time. With the walk rule, the defense could skip that step and simply walk Carl and appeal the BOO without a pitch, no?

How is this officiated under such rules? When can the walk be issued? How long can the offense correct their potential BOO error before the defensive manager pounces? When does the batter or apparently incorrect batter become a runner under the modified rule?