Wood stove "Iron Dog I" .... who knows it?

I believe the question of whether fireclay or cast iron is "better" in the combustion chamber (and by how much the firing or heat storage is more efficient) can be neglected in practical operation—at least when it comes to effective combustion. It's like with soundproofing: to be truly effective, you need mass. A lot of mass. This can only be achieved with a masonry stove. They still emit heat even 12 hours later. Especially with the desired "small" model, which will already be small in size, this plays a negligible role with proper firing.

In the meantime, I have found a detail about the Brunner stove I want that ruins the fun for me. :rolleyes:
It does not have a self-closing door, and on one chimney, only two stoves are allowed if both have self-closing doors.
Because I want to comply with such regulations, that’s not going to work with the dog.

There is already one hanging on our chimney – with a self-closing door – but it no longer closes by itself because the self-closing spring has broken – for the second time. o_O

He does not have a self-closing door and only two stoves are allowed on one fireplace if both have self-closing doors.

Many "cheap" fireplaces do not have self-closing doors or if they do, there is an additional charge again. You should ask Brunner, an upgrade is usually not a big effort.

In an email, the company Brunner replied that the stove "Iron Dog I" is not approved for a chimney with two connected stoves. I assume they mentioned the possibility of a conversion.

Many "cheap" fireplaces do not have self-closing doors

Are you sure about that? We wouldn't have gotten a fireplace without a self-closing door approved by the chimney sweep here. And that was 15 years ago. And we only had the one fireplace on the chimney.

[A] stove on the chimney does not need a self-closing door. Only when there are two is it mandatory.