Glass is designed to not store any user data or custom settings in most cases, therefore the migration to cloud is really simple.
Snapshots
During cloud migration, project configuration changes a lot (Atlassian renames most schemes, groups, workflow details changes, etc.) Snapshots provide a powerful tool to compare configuration changes. Snapshots created On premise can not be imported into the Cloud app, but they can bedownloaded any time and uploaded as a reference point in Comparison.
Glass View Permission
To set the same permissions to Glass, grant Glass View Permission in the expected permission schemes on Cloud as a Jira Administrator.