I receive several warnings along the following lines when using Clientside Validation Webform with the Compact Forms module:

Notice: Undefined index: element_name in clientside_validation_webform_add_webform_validation() (line 189 of /var/www/omi/sites/all/modules/contrib/clientside_validation/clientside_validation_webform/clientside_validation_webform.module).
Notice: Undefined index: element_title in clientside_validation_webform_add_webform_validation() (line 189 of /var/www/omi/sites/all/modules/contrib/clientside_validation/clientside_validation_webform/clientside_validation_webform.module).

I believe the warning is happens because Compact Forms removes the name/title from the webform element before validation occurs. Turning of Compact Forms stops the errors.

Would it be possible for validation to use different handles?

This will happen at any point in the code where we assume name/title exist.