As of April 8th:

100% of "all premium letter" combos taken (abcdefghilmnoprst)
74.5% of "all good letter" combos taken (all letters except QXZY)
51.5% of total LLL.in (all letter combos) taken

A full list is available at NP. Three of us have done the scan and received similar results:
jagusa, iamallanshore, and registerrants.