Ambassador, British Airways; FlyerTalk Posting Legend
Join Date: Apr 2012
Location: Leeds, UK
Programs: BA GGL/CCR, GfL, HH Diamond
Posts: 42,887
The main advantage of option 3 as you note is no cancellation fees and the 241 is kept live regardless of the original expiry date until April 2022. You will need reward availability when you come to rebook.
If your flight is cancelled you can do 1 & 2 without any fee as well of course. Also 3 could be an option again if expiry of the 241 is an issue if you were to refund the booking.