I’m newer to Panthers chameleons myself & thought I would let you know what has helped me a lot. I started with my first chameleon(s) this past March, and decided to brave 3 youngins (2 males, 1 female) at one time. In doing so, however, it has sort of tripled my experience in dealing with certain challenges much like you explain. And, in a relatively shorter timeframe than it might have otherwise.
In trying to navigate cage cleaning in a much less stressful way for me and the animals, I have found it extremely helpful to work around my chameleons’ enclosures on the daily, sometimes multiple times daily, and in places where they can see me and know that I am not a threat; and just because I am around or inside their home, it doesn’t mean that they are going to be disturbed or have to move from that comfy warm spot. Occasionally as well, I might open one up to adjust a branch inside the enclosure, pull out and/or replace plants, talk to them without my hands being involved, or perhaps, what actually worked almost instantaneously…..silkworms! After their very first bite of a silkworm, both young males came down towards me, front and center for the first time ever, and were anxious for more of whatever that was. I couldn’t even get a second worm balanced out on a branch before they would be aiming to take them from my hands. I couldn’t believe it! The female not so much. In fact, she still has never let me see her eat. She is such a proper little lady. She will sit waiting to eat with anticipation until I walk away and am surely to not be peeping from around the corner.
Today, if I go to remove one of them from their enclosure, it is not nearly so dramatic. Sure, one might not crawl down to make it super easy, or step immediately up on my hand when I reach it out, but I am no longer getting that big angry Leno chin and a mouth gaping wide open.
I really do think that my regular, multiple times daily presence, and without any major disruption to them, set the stage and was the perfect way to start and remain consistent. We are still learning one another and building trust, but just in a matter of a few months we had come so far that it was no longer panic inducing for anyone.
I know this isn’t an immediate solution that you were likely looking for, but it is one that Libby Kammerflage shared with me when I first received them. I have been really thankful for this advice, as I’m sure Willow, Nofy, and Sinbad have been too, so we had to be sure to pass it along. Wishing you and yours the very best

Kristina