Unresolved journeys only ever occur when you only touch in or out at a
one
end of your journey and you do not have a valid season travelcard for the zone
that station is in.

Can you just clarify for me please then, an Oyster card with a season ticket doesn't always need
to be touched in/out.

For example, the barriers at the end of my journey covered by a season travel card are open. Do I
need to touch out.

No.

For example, touching in at North Acton, do I need to touch out using the platform validator at
Ealing Broadway before boarding a NR train?

No.

First example is not to inconvenient, the second can be at busy times.

You only ever need to touch in or out if *some part* of your journey will be
using prepay.