Hi,
Having a custom field of the type tags is a great idear! Please add a feature request about this on Acyba's website (https://www.acyba.com/community/feature-requests.html) so other users can upvote it.
Meanwhile you can use different custome fields or a custom field of the type checkbox that will hold your tags.
You can use mass actions to set the values of your custom fields.
Please have a look at version 6. It offers way more possibilities to set custom field values. You can safely install it next to v5 (both use their own database tables) and do the migration at a later time.
