No, currently Typeset editor does not support Grammarly. Since you might face some issues, we would advise you to switch off Grammarly while using Typeset editor.
Typeset editor comes built-in with a spell check and grammar check tool which is available for free for all users.
We are also working on Grammarly integration with Typeset and this will soon be live on the platform.
Have questions, concerns or suggestions? Write to us at firstname.lastname@example.org or talk to us on Chat.