One enhancement to incremental ingest that I’d find useful is that ability to work with multiple pc / macs. I don’t use the same Mac every day. If I have ingested some pictures onto one machine on day 1, shot some more on day 2 and tried to ingest just those on machine 2, I still get all the day 1 pictures on the second machine (except with the incorrect, day 2, metadata).
Setting a user-settable cut-off date/time for the imported pics would be one way of addressing this requirement.