ioGates can handle different metadata types and you can find them under the Metadata menu. Any Metadata can be displayed on the sharing page and you can from the share menu control what of the Metadata you would like to display. You can search on Descirption - Meta Tags - Filename.
Meta tags is where you can type in real meta tags and then search on them. There is no limit to how many entries you can have.
It is possible to preset the" Name" field from the preferences menu, so all files that are ingested will have a fixed set of names tags, then it is just the values field that need to be filled in.