Tested with notification off. Untill Amber is back from background, no action is usually confirmed. Amber is quite often missing from the list of 'Active apps'.

Don't know why, so many remain there all the time. So far not working good with this setting.

Can the relay connected notification info list be configurable, by default, to display as a single row only, matching the screenshot above?

In some future update.

The 'roll it up' doesn't remain in effect and list often reappear back in full length.