File attachments additional metadata fields with no database mapping

We are still in pilot phase, but looking at how we want to attach files through Epicor Kinetic. We are SaaS so latest and greatest version and trying to push the web based UI with minimal smart client usage for admins only.
We have found that SharePoint appears to be our best choice. We have ECM, however the quantity and size of our files would quickly outpace the size limits in ECM also we have had poor experience with ECM so far, perhaps we are missing some set up.

At this point in time we are looking to add extra metadata fields to track information. I know I can add metadata database mappings however I want to simply add metadata fields that are entered manually.

Those 2 fields are hard coded from the begiining of the time.
Your only option is metadata mapping in the database.