The way to switch between Bank/Play mode on all three over MIDI requires an aux switch.
Connect an aux switch to the master stompbox and assign one of the aux switch buttons (TIP, RING or T+R) to change Bank/Play mode. This is done in the AUX SW menu of System mode.
Then in the MIDI menu of the master pedal, go to XMT CC. In the left column find the aux switch that you just assigned (either TIP, RING or T+R) and in the right column select a MIDI CC that you'd like to transmit this message on.
On the slave stompboxes go to the MIDI / RCV CTL menu and assign P/B (Play/Bank) to the same MIDI CC number that you just set on the master.
Glad you found the videos helpful. There isn't currently any more MIDI documentation for the Eventide pedals but there is a wealth of MIDI info on the web. Since MIDI is a standard protocol the MIDI tips and tricks to be found can be applied to most all MIDI gear, including Eventide stompboxes.