I agree with all of the above suggestions. Deleting or archiving signed quotes that have errors, need updates, or were never paid would be a great way to keep HubSpot clean and organized. If there is concern about losing critical data, HubSpot could require approval to delete a quote. Additionally, adding the ability to tag quotes with properties would be a helpful way to filter out quotes that should not be used in a report. For example, you could tag quotes that are for internal use only, or quotes that are no longer active. This would make it easy to find the quotes you need and avoid including irrelevant data in your reports.
This issue was first reported over 2 years ago and seems at the surface to be a small ask?