You have been given some good reading and great advice.
I too have an aggressive glider and it took 9 months for her to bond
with us. She still has her moments but it's usually when she feels stressed. Most of the time she is really sweet.
It wasn't easy taming Dot. She would rather die fighting than calm down. It was dreadful. So what I did was leave her alone and play with Fiona. Dot watched. Fiona was already bonding
with us when we got Dot. Fiona got a lot of attention and Dot didn't seem to care. What Dot did care about was sleeping alone during the day when Fiona wanted to spend time in the bonding
For a time, we fed treats to both of them through the cage bars. It didn't always work. So when Fiona in the bonding
pouch I would coax Dot treats through the cage. It worked out better.
Tent time was very difficult too. I would take them to the tent just before they were up for the day in their sleeping pouch and Dot wouldn't go back to the pouch. We learned that morning tent time was much easier. They are both sleepy and are willing to go back to their sleeping pouch when tired. Treats in the pouch help too.
Once you feel you are making a little progress with him the next step I learned (the hard way of course!) Was who gets "The last word "? Me!!! Still to this day... It's kinda hard to explain but they unlearn what they learn. Right now he bites because he is scared' and has learned "The hand " goes away. Have you tried saying " Tssss! or Sssssst!" (it's glider talk for I don't like what you did). It doesn't always work at first but he is listening. It has to be done instantly as he bites. It communicates to him and eventually they listen.
He is mega scared and he doesn't trust at all. Lots of patience...
Oh and when you absolutely have to catch him do continue using fleece between you and him. It's better if he is mad at it than you.
Back to who gets the last word... When you are carrying him alone in the pouch and he starts crabbing and lunging, rub and talk soothing words, sing a lullaby softly till he stops. Sometimes they just need comforting. He needs to learn you are safe and you're not gonna eat him.
To this day Dot will crab at me hanging in her sleeping pouch in the cage. All I have to do is rub the pouch and sing to her. She knows when she quits, I will stop and go away... lesson learned and I get the last word in.
Long story...sorry... hope it helped to know you are not alone... There is a thread in here somewhere called " The FIST prevails!" It is good reading once you can calm him down a bit.
Please keep us posted and ask more questions if needed.