Clive, in your X plan setup do you also have the Intergas cylinder sensor connected?

I set my boiler DHW temperature to the same DHW temperature as EvoHome. When DHW is scheduled and the cylinder temperature is less than 5C below the set point, the Intergas boiler switches to mode 6 and reheats the cylinder at a higher temperature and power setting. This works around the CS92 slow response, as the boiler will stop heating based on the cylinder sensor. I don’t see any overshoots.

There is a BDR91 that short circuits the cylinder sensor when DHW is scheduled off.