Are complicated controls/thermostats/hydraulics needed for ASHPs at all?

Greetings BuildHub'ers! 😄 I am grateful to have you here, as in my County, ASHPs are only started to get installed in the recent years, so few experience is available. Now, they are installed like there's no tomorrow, but the hydraulic and control 'finesse' is completely missing from most of the installers inventory. Basic 4 port normal buffer tank with huge coil surface area DHW tank. AA battery powered on-off thermostats, no statified tanks, no 3 port configurations, no extern

Thanks again for this @Gary68. I had another go with it, and actually got something working very nicely (in terms of performance in practice, most definitely not for elegance of design). 1/ Loxone uses dry contact inputs to control call for space heating (UFH and FCU zones based on room stats and house occupancy), and also sets the "Smart grid - On recommendation" inputs to FTC (based on excess PV generation, or octopus Go cheap rate) 2/ The ecodan FTC local controller has a s