'Pencil tool/Draw free form' in Comments tool can be used to draw/write freely in Adobe Reader and Adobe Acrobat. if your device supports the functionality of wireless pencil, then you can use the Comments tool.
Note: You cannot write directly on a PDF, only Comments tool can be used to write on a PDF. For detailed information, refer to Adobe article Use annotation and drawing markup tools to add comments in PDFs, Adobe Acrobat and Acrobat Reader
As of now, there are no such features available in Acrobat or Adobe Reader which lets to edit/write using a wireless pencil.
You can use the Adobe wish form to request new features or request modification on the existing feature Feature Request/Bug Report Form
Feel free to update this discussion for any further assistance.
Thanks, I am thinking that current tools are a bit clumsy that is why a wireless pencil would be perfect.
But I’ll put the place which you mentioned my wish.
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