[Feature] Quicker duplicate detection during import

[mattalxndr]

Ever considered expanding the functionality to include an event listener than checksums during import and basically says "yeah we got those already"?

[geigerzaehler]

@mattalexx That sounds like an interesting idea. Is it something that would be useful to you? Would be great to understand the use case a bit better, e.g. which problem it solves.

Also, would you be interested in implementing the feature yourself (with my support)?