MagicMirror is licensed under the MIT. And most of the more than 1000 modules are also available under a free licence. So as long as you comply with the licence conditions, the answer is yes.
Of course it would be cool if you would give something back to the community, be it through donations, code improvements, documentation improvements, helping others in the forum or something else. It would be interesting to know if Waveshare returns anything 🤔