Heat buffer - how to connect it to a solid fuel boiler

How to connect a heat buffer to a solid fuel boiler and to an existing central heating installation. Diagram of connecting the buffer to the boiler. Advantages and disadvantages of the connection method compared to the existing installation.
I would like to point out that my existing installation is not without flaws, it could certainly be designed better somehow. e.g. I would replace the three-way valve (the one for the underfloor heating) with a 4-way one, then we have more control over the temperature going to the underfloor heating. Well, that's what I had done before and I didn't want to change it when connecting the buffer to the existing installation. This was not my intention when creating this film.
I would like to present an alternative, in my opinion much more advantageous, of connecting the buffer to a solid fuel boiler.