Hi Donald,
Our client has purchased the Helix Ultimate.
This is totally free template. Everyone can download it without paying. So I guess, we talk about premium template based on Helix.
If we talk about technical details. In general this template consists of two parts, template files itself and Helix Ultimate plugin files. If in Joomla you make template copy - it's still the same template files. The only difference is a separate table in the database. You can see it for all Joomla templates.
It means that when you update template or plugin itself, it will be updated also for template copy.
Manual update is required only if you changed the template name by editing the template files (.xml, .php and folder name etc).