Yes - the staff can provide some cables, adapters, and chargers. Note too: there are a few tables that have USB and AC/DC ports at McKim's - it's just not at all the tables. Generally the larger round tables for 4 have them - the table I was at yesterday was the 2nd in from the door and had both USB and power plugs.
Another nice thing - it's generally much easier to get into now - the wait is rarely more than 15 minutes with no MMB. Yesterday I generally was a walk-in - I gave my name and number, stepped aside to wait, and within 60 seconds, got the text to get in.