We have a feature branch we create a PR 1 to SIT -> we merge the branch -> deploys to SIT -> we delete the branch
We have a feature branch we create a PR 2 to SIT -> we merge the branch -> deploys to SIT -> we delete the branch
now both PRs are in SIT branch
we make a PR from SIT to UAT -> Both PR's are validated against UAT -> if all is good both PR's get deployed to UAT
but then Monday comes and business wants JUST PR1 to be deployed to production
so we make a PR from UAT to the main branch which is merged -> then we trigger the manual comparison and go through the PR files list to add them manually
instead, if we could have just cloned the deployment triggered by the PR1 and pointed from the main branch to production will be much quicker and easier
PR2 is merged to the main branch but it's not really ready for production
so when the time comes for PR2 we can refer to that very first deployment to clone it
in a perfect world, all PRs go at the same time but in most cases, this is not the reality