If we go for the low hanging fruit first, do you think you could still live happily with your DHW tank heated to 45C rather than 53C? (Please make sure your sterilisation cycle still happens once a week to 60C). Using an online calculator it says you use 2.6kWh of energy to heat 280L from 45C to 53C. Yes, the heat pump could have a COP of 2.5 to 3.0 when servicing DHW, but this still adds up over the course of a year.
Likewise, do you have the heat curve set on the UFH as low as you can tollerate, but high enough that the rooms stay warm?