Rationale for the above:
1) Change/improvement has been so small for me the last three releases;
2) Would enjoy production firmware (2021.40.5.1) features more then beta FSD right now, such as active road noise reduction ("ARNR")- more useful (to me, anyways)
3) 10.x series releases are hard on my Plaid's steering and braking components.... And I just had my half shafts replaced due to that vibration issue
4) Large efficiency hit using beta FSD, when combined with the cold and rain here
5) I can always opt back in, at any time, per the reply I received from Tesla betafsd team (see below)
"Hello Xxxx,
FSD Beta 10.4 will be removed from your vehicle shortly. To ensure you do not receive future Beta updates, please go to the Autopilot UI and select Controls > Autopilot > Request Full Self-Driving Beta, which will trigger a pop-up which will then present you with the Opt-Out button. You can opt back into the FSD Beta queue at any time by selecting the Request Full Self-Driving button.
-FSD Team"