Hi Harry.
Firstly to introduce myself and seek a clarification. I'm the Talent Experience Product Manager. To clarify are you talking about Learn Appraisals?
Appraisals stopped being developed when Perform was introduced in v13. Any enhancements to the performance management tools will be made in Perform's features.
To that
Given HR ware wishing to review these documents I assume they hold some formal status. The best way to store and review formal content is using the evidence feature, so they user can upload 'evidence' as a file. Then this evidence can be reviewed using the review question type in a performance activity. This review can include an Appraiser.
I hope this helps