How helm hooks works on Rancher?

I’m developing a custom helm chart for my deployment, and I strongly relly on releases hooks, “pre-install”, “post-install”, “pre-upgrade”, “post-upgrade”, “pre-rollback” and “post-rollback”.
It works very well on vanilla helm, but I can’t figure out what is wrong with Rancher Helm.

It seems that Rancher executes hooks on a odd way, just after install it fires an upgrade hook. Sometimes, after an upgrade, it fires two upgrades in a row.
The pre and post-rollback hooks did not work as expected too. It runs a upgrade when I request a rollback.

Someone have any doc to point me?

There is no better doc than the source-code itself …

I just looked at common.go … It only calls “helm upgrade --install” and “helm uninstall” commands; “rollback” and “install” are never called, so the hooks are not going to work!

It makes sense to use "helm upgrade --install’ instead of “helm install”, even though it could be the cause of an upgrade just after the instal.

But I did not understand why not implement the “helm rollback” command. Is it a design choice or may I expect this feature in the future?

For now I’m considering to use plain helm instead of rancher charts.