Example:
When I already selected metadata filter with many items, downloaded metadata, compared, checked, and clicked deploy then I am getting an error that some dependency is missing but it is metadata type that wasn't selected previously.

Currently:
I need to click refresh comparison select additional metadata types and reload all metadata from both sandboxes. It is very time and resource consuming with big packages.

As a solution:
I want to have the possibility to click a button and select on the metadata list only those that I want to add to the current package and only those should be downloaded and extend current package.

Benfit:
Quicker adding missing metadata dependency. Only new metadata type is added.

It is similar to this idea https://gearset.uservoice.com/forums/283474-help-us-improve-gearset/suggestions/39251272-refresh-specific-item-in-comparison-through-contex but here I want to load metadata that were not on the list previously.