This allowed me to easily add a second tier above my 18953, where I put my laptop for years with no problem.
However, despite the supposed 30kg load capacity of the stacker, I'd never trust it with anything weighing more than 15kg, especially if it's expensive equipment.
I feel like the force of pushing down keys on a keyboard was not taken into account when the "30kg" value was being determined.
For a laptop, a mini-synth or a synth module it should be perfect though, and it's also fairly easy to assemble.