Respect the Windows 10 global spellcheck setting
Windows 10 allows you to disable spellcheck globally. This is important to customers who write in more than one language. Almost no UWP apps from Microsoft respect this setting (OneNote, for example, ignores this as well).
Spellcheck and it's annoying litte red worms are real frustration. Why do you assume that we all want spellcheck everywhere?
Totally agree with this suggestion.
Yes, please let us turn it off. Either by respecting the global setting (best), or in Teams itself. Usability/readability is more important than the occasional real spelling error that gets through.