Which instant water heater for the kitchen sink?

I would have to check to find out how much pressure is present. I thought for a sink more like 5 liters/min (good that I asked here). What would you do here with the 11m? Connect to the heat pump, or connect an instantaneous water heater? (or is there also the option to install a small one in between? [müsste halt der Durchflussminderer ausbaubar sein])

I would have to check if I can find out how much pressure is applied. I thought more about 5 liters/min for a sink (good that I asked here)

Normally it is 3-4 bar. Not too little, so that in case of doubt there is enough water pressure in the shower. Ask the plumber who planned the line.

What would you do here with the 11m?

Heat pump and no instantaneous water heater, unless you need hot water extremely frequently. So occasionally washing pans by hand, the rest goes into the dishwasher.

Yes, exactly, only rarely for rinsing

Dishwashers are usually connected to cold water, at least that's what I thought.
I only know of a few devices that have a separate hot water connection.

Dishwashers are usually connected cold, at least that's what I thought.

That's how I mean it too. Everything (possible) goes into the dishwasher. For the rest, the hot water connection. Then you can also wait a few seconds.

We have a solution with instantaneous water heaters and a hot water heat pump. The main reason is that the two children’s apartments are only used sporadically in the long term, and I did not want to have hot water standing in long pipes for an extended period. Another reason was that we were already annoyed in the house before that it took a long time for hot water to arrive, and I wanted to eliminate this situation for the children as well. With frequent use, the connection to the hot water heat pump is cheaper. With us, each unit is a 17kW Stiebel Eltron device. Since the electricity network provider does not permit two instantaneous water heaters on one house connection, we have two connections and meters. That also incurs costs.

In your case, significantly longer pipes if these are separate apartments, right? So also no instantaneous water heater behind the hot water connection of the heat pump, right?