Support of Command beans with @Validateable annotation

I have RegisterCommand used in register action.
This command is marked by '@Validateable' annotation.
When I try to render form with it, I get org.codehaus.groovy.grails.web.taglib.exceptions.GrailsTagException: Tag [all] currently only supports domain types.
As I can understand, it is possible to implement this feature.
Could you implement it?
Thanks

Start with the RegisterCommand marked with @Validateable and reproduce the form rendering failure from the [all] tag. Trace the form-tag path that raises the GrailsTagException and determine the existing domain-type restriction. Done means the form renders successfully for a command bean without that exception.

Written by the indexing model from the issue text.