Question How Early Should I Arrive at T5 from Sofitel Heathrow?

[LocalsAndLands]

We're staying overnight at the Sofitel Heathrow and have a First Class flight out of Terminal 5 to the US at 9:50 AM on a Saturday. British Airways recommends being at Heathrow security 3 hours early. While I usually prefer being early rather than late, this seems a bit excessive, especially since we're already at the airport. Has anyone else stayed at the Sofitel and flown out of T5 early in the morning? How early did you arrive at security, and was it enough time? Any tips or experiences would be super helpful!