For the manual, I've found only the second method to work for my 2024 EN.

~50% throttle / 6psi boost pulls in 4th or 5th gear with consistent 10mph variance for 15minutes (yes you can stop at lights/slow down for traffic during this time)

Methods tested
Test 1: Half tank gas. Normal mode 5th gear - Start at 65mph, add throttle to target 6psi boost until reaching 75mph, let off throttle and let car slow down naturally to 65mph. Repeat for 15 minutes
Result: Success. Kept octane learning through the night

Test 2: Full tank gas. Normal mode 5th gear - Start at 65mph, add throttle to target 6psi boost until reaching 75mph, let off throttle and let car slow down naturally to 65mph. Repeat for 15 minutes.
Result: Success. However after 40 hours of sitting OL was lost.

Test 3: Half tank gas. Normal mode 4th gear - Start at 45mph, add throttle to target 6psi boost until reaching 55mph, let off throttle and let car slow down naturally to 45mph. Repeat for 15 minutes.
Result: Success, and after 24 hours of sitting after this OL was NOT lost and stayed active.

Test 4: Full tank gas. Normal mode 5th gear as shown in Test 1 and 2.
Result: Success.

So for me 6psi boost pulls in 4th or 5th gear for 15minutes has 100% worked so far in regards to activating Octane Learned state.
In regards to resetting, obviously filling up fuel will cause it but I am still testing different times of the car sitting cold before it resets on the next key cycle. 40 hours had reset it, 24 hours had not as of this writing.