Traditionally, chimneys have been built from the ground/rock. Heavy pieces. Then, tiled stoves must be connected horizontally.
A tiled stove never carries the chimney above, but with modern modules, it can be above. But not on. That is, the chimney is supported by something other than the stove.
This allows for easy renovation of the stove, without the entire chimney collapsing.
The installer knows this.