Hi ajd3rd,
I was searching for a similar solution, where i need the draft email to sit in the draft mailbox of the user that triggered my instant flow.
Based on your creation above, i found that the below screenshot worked for me:

Picture 1 just shows the Flow Structure of my Instant Flow. For Selected Item and Get Item is Simple. i just need to choose my site and list correctly.

Picture 2 is just the conditions for my flow to run.

Picture 3 is the Yes/No Condition and what is the URI i used. What is important is to use GET USER PROFILE as there is more than 1 user using this flow.
As u can see, its a mixture of what u used (mailfolders/drafts) and what i used previously https://graph.microsoft.com/v1.0/me/messages
Hope this helps!!