Split air conditioner -> Which multisplit configuration?

I am currently planning the air conditioning for my major renovation.

The rooms to be cooled are:
Bedroom approx. 15m²
Office approx. 15m²
Living room approx. 35m² *
*also to be additionally heated on very cold days alongside the heat pump

For the air conditioning unit, I have chosen Bosch devices.
For me, there are now two options to implement this:

Option 1:
One multi-split outdoor unit and three indoor units
Outdoor unit: CL5000M 79/3 E [7.9kW]
2x indoor unit: CL3000iU W 20 E [2.0kW]
1x indoor unit: CL3000iU W 35 E [3.5kW]
Price approx. €2116


[second column]
The 7.9kW outdoor unit has a minimum cooling capacity of 3.03kW
This means that if only one of the 2kW indoor units (running at full power...) operates, the outdoor unit already starts cycling (=higher power consumption and wear).

Therefore, I am considering...
Option 2:
One multi-split outdoor unit with two indoor units for the office and bedroom
Plus one single-split outdoor unit with indoor unit for the living room
Outdoor unit (1): CL5000M 53/2 E [5.3kW]
2x indoor unit: CL3000iU W 20 E [2.0kW]
Outdoor unit (2) / indoor unit: CL3000i-Set 35 WE [3.5kW]
Price approx. €2376


[first column]
The multi-split combination here has a minimum cooling capacity of only 1.7kW
Regarding the piping route (cooling lines), it actually makes no difference whether I place one or two outdoor units on the flat roof of the extension.
Also, the price is similar here (Option 2 is €260 more expensive)
Which option would you choose?
(a photovoltaic system West/East 15kWp is available; nevertheless, you don’t want to consume more electricity than necessary and the service life of the devices is also a factor)

Get advice from a professional. You’re not allowed to fill it yourself anyway… Depending on the setup, you might also need a switching box, etc. Line lengths and height differences also play a role. Single splits are often more sensible. I would do that here as well. They are probably all single-phase. Then one phase per unit. I would rather look at the Asians (Mitsubishi, Daikin) Pre-filled units are now also prohibited.

For what reason would you completely recommend Single Split here?

Where is it stated that pre-filled devices are no longer allowed?
Daikin and Mitsubishi are simply significantly more expensive and for the two months a year they run....

What do you mean by "switching box"?
Actually, the indoor units are directly connected to the connections of the multisplit outdoor unit.

Prefilled devices may only be connected by certified specialist companies.
Therefore, they are basically prohibited for private individuals.
You need a certified company to fill the system.
However, the specialist company will gratefully refuse if you have not purchased the material from them.

Whether single or multisplit is always situational. An "Umschaltbox" may be necessary to balance pressure differences.
Whether everything is connected directly to the outdoor unit or maybe 2 devices on one line... depends on the conditions on site.

I would find a specialist company and talk to them. Sure, it will be a bit more expensive but then everything will be fine.
Bosch is not really a major player in air conditioning. I don't even know if they build them themselves.
If it has to be cheap, there are many other Asian manufacturers.
But even here I would talk to your specialist company. They can also offer affordable options.
Possibly they will agree that you do things like the drilling yourself to save some money.

If you are so afraid of short cycling, just take the third device larger. Then theoretically the performance is not enough to fully supply all indoor units, but the system will not short cycle. As long as you turn it up fully. In reality, however, the systems often run in part-load mode. So you will have problems with short cycling anyway. With singlesplit you have smaller outdoor units that modulate further down. Shorter line lengths... Usually not really more expensive if you also include the piping and so on.

The issue with the specialist company is known to me and I already have someone. However, they only do the commissioning.

It is about €500 more for three individual units compared to a three-unit multisplit.
The question is how long they have to run before that cost is recouped (especially with the photovoltaic system).
The smaller outdoor unit from Bosch unfortunately only has connections for two indoor units, so it is ruled out.
In terms of wiring, I don't save much because the spot on the roof is actually ideal for all three indoor units and I don't want to hang the outdoor units ugly on the facade either.

Then do it as planned. It will work out. And keep it to yourself if someone does it for you without certification;)