Cooling with heat pump via underfloor heating?

We have also had a brine heat pump with passive cooling in operation for 1 year and think it's great. I can confirm the mentioned 3°C difference, of course shading is still necessary, otherwise the heat input is simply too high. The cool floor does not bother us at all, on the contrary, it is even very pleasant during extreme summer heat. With tiled floors you can notice it more clearly, whereas in rooms with laminate you can hardly detect the difference of cooling on/off by the felt floor temperature. The biggest plus is also the low electricity consumption, since only 2 circulation pumps have to run. We are still looking for a solution to just one problem. Since the heating circuits are set according to thermal balancing, the required flow reverses during cooling. The bedroom has the lowest heating water requirement but the highest cooling demand. That means adjusting the flow rates twice a year. Are there actually control valves that can hold intermediate positions? KNX is available in the house.

2 boreholes of 100m each

Normally sufficient (50 W/m) for a 10 kW heat pump.
350 sqm, Zugspitze or drilling "simply just oversized"?