Also our SOPs discourage monitioring of slow trends by having the engine instruments displayed
Airbus SOP's encourage the monitoring of all systems at regular intervals in the cruise, precisely in order to spot slow trends - I bet your airline does too. Every 30 minutes recommended - most pilots seem to do it more often. Pop-ups are great for a quicker parameter change, and give you time to analyse the system and think about a course of action before ECAM gives a warning.
It's not just about engines, what about Hyd Qty, IDG oil temp etc. The Cruise page has engine oil quantity and vibration on it - but also the very important Cabin Altitude, so best to leave that displayed when not checking a system.