I would like the ability to make comments or underline or add other drawings on top of the text in a note. Right now a drawing or other handwritten items are an attachment.
Drawing on top of the text doesn’t really fit our model. For that you would probably want a handwriting note app like Notability.
If you want to make comments etc about an Agenda note, I recommend exporting it as PDF, then importing it again as an attachment. You can then open it for editing, draw on top of the PDF, and save again.