We're working on a migration from Classic to LEX. However, it will be a long transition, so we need the ability to work in both for as long as possible. The documentation states/strongly implies that there should be an ability to leave an action override in place in Salesforce Classic, whilst removing it in Lightning/Mobile:

Remove Overrides for Standard Buttons and Tab Home Pages (https://help.salesforce.com/articleView?id=links_customize_override_remove.htm&type=5)

However, step 3 describes options which not available within our org (See attached screenshot):

"Select No override (default behavior) for the experience whose override you want to remove (Salesforce Classic, Lightning Experience, or mobile)."

We've had a case open with Salesforce for a few weeks now and I can't seem to make any headway (they say the documentation team say that their documentation is correct, but also can't explain why I don't see the options that the documentation says should be there) Being able to switch off the override in LEX would be ideal (and also expected, given the documentation)

As we're in Lightning Console, using additional Lightning Components to override the override behaviour specifically for LEX still results in unwanted behaviours (console tabs being opened unnecessarily when editing, no access to inline editing on the standard Lightning Page, awkward navigation bugs occassionally, etc.) The only option remaining to us may be to have to re-build an object model specifically for LEX, which I'm sure isn't the desired approach when migrating to LEX

Is anybody able to confirm which is the expected behaviour and best practice for dealing with it?