Minimal flow requirement for a domestic heat pump

Greetings

I'm working on a air-water heat pump system for a residential building (both heating and cooling) using split system heat pumps.
I'm wondering what the 'minimal flow requirement' on the water side means exactly - is it just centrifugal pump protection - requiring only minimal 'FLOW' as stated, or is the requirement for 'FLOW at a delta-T' implying protection for other elements of the heat pump (eg. ensuring sufficient evaporation/condensation in the inner unit of the heat pump).

I'm asking this question because of space limitations - they are for small apartments and space is too scarce to fit even a small buffer tank - thus I have to be creative in solving the problem and ensuring the heat pump doesn't go into a blockade every 5 minutes.

The installed heat pumps would be Viessmann Vitocal 222-S units, but I imagine every split air-water unit on the market has a simialr 'minimum-flow' requirement.
The water side consumers are a combination of floor heating, fan-coils and a bathroom radiator.

Thanks in advance, hope the question wasn't misplaced