Filter leads last contacted more than X days ago

We want to delete old leads. We don’t want to delete “completed” leads since leads are completed immediately after sending the last email in the sequence. We want to keep them around for a few days after we send the last email.

I was told this was possible as it was a requirement for us to switch to Instantly. However, it isn’t. There is a filter by “Last Contacted” but that is <= X days, not >= X days. It seems trivial to allow the UI to select within or more than and adjust the query accordingly.