I just got a pop-up for Extended Options trading:
8:15P-9:25A EST
SPX, XSP, VIX, RUT
I received it by searching for ticker SPX.
Edit 4/24: Only available on Robinhood and IBKR.
Also I’m fairly confident if you open a position at 8:15 and sell before 8:15 the following trading day it will count as a Day-Trade.