Yes, that is correct, The bleeder allows getting the most air out as possible.

These heaters are hot all summer, they use a blend valve that diverts the airflow either through or around the heater core.
All of the air passes through the AC core all the time.

For a heat exchanger you want to pass though the HE first then the heater core. The other option is a parallel system which if I am correct how the rear heater is plumbed.

Good to see you have the system cleaned up an functioning before it gave you big issues this summer.

Cheers, Charlie
If It ain't broke, Modify it!
87 Montero turbo Converted back in Spring1989
95 Montero SR 3.8 DOHC Only one?
93 Pajero 3 door 6G75 Mivec with paddle shifted 5 speed
Then a Gen2 SR with full coil independent suspension.