Preview currently as a number of limitations, which we are working to remove in future releases. That being said, we attempt to clearly communicate any current limitations. Please let us know if any of these limits are a blocker to your use of Preview in order to assist us in prioritization.
Each Deployment that Preview manages is created with resource limitations in place. While these should be high enough for most applications, they are currently not configurable via user configuration. Please let us know if you are experiencing resource issues, and we are able to adjust your Deployment resources on our end.
Non-namespaces Resources are currently not supported as part of Preview Deployments. That is to say, an application deployed by Preview can not create new Custom Resource Definitions (CRDs), or new non-namespaced resources.
If you are using a self-managed cluster you are able to deploy any CRD you wish as part of cluster provisioning, and then make use of those resource definitions within your Preview-deployed app.
This also means that charts which create CRDs should not be used as application dependencies. At the very least, if your dependencies do create CRDs, ensure that dependency versions are consistent.
Applications which purposely distribute components across multiple namespaces are not currently compatible with Preview. This is a result of Deployments being limited to a single, Preview-named namespace.