What ended up working best was enabling both the direct visibility and refraction overrides, then setting both to black. The video only mentions the direct visibility override, but that alone didn’t do it for me in this case. I needed both overrides set for it to work.
Affinity is most likely your best choice if you are trying to composite any transparency in integer formats. It offers blending with gamma 1.0 as a per layer option and not global setting as PS. Example png with matte object attached.
Wow! Really?. DID YOU EVEN READ ANY OF MY POSTS? If you did, you would know that this issue has been already resolved (and it had nothing to do with alpha channels!). This is not the kind of response I expected from someone here. Very disappointing and unprofessional.
Anyway, I wish you all the best.
The important thing here is that the original problem is solved. If there are any outstanding issues or questions, it’s ok to discuss them if needed, but let’s be respectful.