We have a setup where the clusters cannot reach the git repository https://git.rancher.io/charts. Our solution was/is to mirror this repository and add a new url to the cluster catalog. Then we get the charts that are available upstream but the cluster tool page doesn’t work anymore because the URL has changed.
From my point of view it would be better if the check for this page only checks the name of the catalog so that we can enter a reachable URL.