No face cut? Just a backcut with a pole saw? Wow.
OK, how deep and how wide a face cut do you think you'll get before all that weight in the head pinches the chain/bar or isn't that going to happen ?
Are you entirely certain, given the shelly look of the trunk in the second lot of pics, that its not going to fail while putting in the face cuts ?
Unless you have a very long bar, when you are putting in the face cuts and can work without getting under it, then you're on the wrong/dangerous side of the tree, you comfortable with that ?
Why would you get all but under that trunk and under the direction of fall ?
The splintery looking pieces in side the trunk "may not" be adding much strength to the trees ability to remain standing, if that's the case the shelly outer
wood is indeed heavily loaded given the huge weight up high in the head.
These are the reasons I would consider it to dangerous to put in a facecut. An onsite inspection may change that view.
Given the probable shelley nature of the trunk a pole saw offers safety in the distance you can stand back from the tree and detect the very first movement.
Laugh at the polesaw if you like, mine cuts 9 or 10" eucalypt limbs on occasions and has plenty of ability in that regard.
Sometimes fallers get caught up in doing it their way and can't open up their mind to alternative methods or equipment.
No expert btw, but no beginner