We do the home service when/if asked and reset service interval using the manual method on the car, this resets the oil dilution etc back to 0% etc and then we have a full annual service at the main dealer based on age even though the car doesn’t say it needs one.

I suspect most people suffering with oil dilution issues only need servicing on age rather than mileage. We’ve only got 55k on our 15 plate for example! MY17 Santorini Black L494 Autobiography 5.0 SC - Sorry!
Previously Bell a 2015 MY16 Loire Blue Autobiography 4.4 SDV8
Previously George a 2007 MY07 Java Black VSE 3.6 TDV8
Previously a 04 MY04 Defender 90

Are more frequent oil changes also recommended for the 2l engine (P400e)? 2025 P550e AB

The P400e is a petrol engine and does not have a DPF so should not suffer normally from fuel dilution.
Just follow the service request on the Incontrol app or on your dash 2018 SE SDV8 4.4 Byron Blue