Currently, when the filter selected by the merchants return no product in the editor, a simple label saying “No results found.” is shown in the editor.

We want to improve this UX. Whether we can do it or not, is currently a bit of an unknown, as the “No results found.” is handled by the “Post template” block in Gutenberg (packages/block-library/src/post-template/edit.js:L234). My hunch is that we can probably do it by using a HOC. But this issue should also be considered as a research spike into whether this is relatively easy or not.