Hello!
Previously we were using Atlassian Connect dialog to open our plugin throughout the jira in dialog.
Currently, when we are migrating to Forge something similar seems to be available when using Command palette Forge module.
However 2 major limitation exist:
- viewportsize or sizing of modal is not available and default size is not always suitable
- displayConditions for the modal is not supported
Is it going to be implemented by Atlassian team in the nearest future?
Global dialog from Jira side menu would work great for us too 
Best Regards,
Oleh