Help with Heading Cut on Esk Sunset Maple

My several year old Esk Sunset maple (grafted) got some sort of bark infection/damage that caused significant portions of the cambium to die. I took a hawk bill and carved it out but it was significant enough to cause a die back this season. It has a Esk Sunset sucker growing out that I would like to let take over (there's also rootstock suckers). I cut the trunk off pretty high from the sucker to get the debulking done, but I'm unsure of how close and what angle i should take it down further. What's the appropriate cut for this situation?

https://www.imgur.com/a/QXtLs64