The maximal value of 35 kg I would consider as the extreme maximum and then only in non-solid supports.
But what I have to complain about and it is also a point deduction is the Defective Product description:
No puzzle: comes pre-assembled to them
If that had not been expressly thereby, it would have been I do not care, is now really no art the little thing (especially with the manual) to put together. But explicitly referencing a pre-assembled item and then send a kit I find then yet strangely ;-)
But otherwise a quite chic and fairly inconspicuous wall bracket for easy microwave or pizza ovens.