how to test android security patches before they are pushed OTA

I have been looking all over for an answer to this issue and would think that our company is not the only one that has this need. I need to test proprietary apps with the monthly android security patch before the patch is pushed OTA to our workers' Samsung devices to ensure that the update does not result in breaking functionality of our apps.

As I understand the process, Google comes out with monthly security updates which is provides to manufacturers. The manufacturers incorporate the security patch into a release and then push it out OTA. So the update actually comes from the manufacturer rather than Google.

I've contacted Samsung Developer support and received multiple responses stating that they do not offer the update for testing prior to pushing the update to devices. I asked about

So here I am. I've found so many answers from Stack Overflow throughout the years. I did not see this question asked. Has anyone has done this or have an idea of how to go about testing the monthly android security patch prerelease?