OMG. Or should I say: O (class)... MG. I got it!

After reading OMAAT's report that F award seats appear right at 1 PM Pacific Time, I've been watching the SFO and LAX to FRA flights at that time every day to learn Lufthansa's pattern.
Business class seats appear at different times, not especially at 1 PM. Since about the 10th of August I've seen only a few F seats appear, generally for Tuesday flights. When they did appear, it was at 1 PM exactly.

Three days before departure, my Sunday flight still had 8 unsold business seats and 3 unsold F seats. Based on that, I liked my odds. Still, after seeing LH business award seats appear and disappear twice and only rarely seeing 60k business seats on United, I decided to lock in a 70K Lufthansa business seat and pay the change fee. I asked the phone agent whether a subsequent change to F would incur another fee. She gave me an unofficial indication that the fee would likely be waived, but no guarantees.

At 1 PM today, 26 hours before departure, I checked for F seats. Three of the 8 F seats were still for sale but there were no award seats. At 1:20 PM I gave up. Around 2 PM I used the United app to check availability, but there was still only business class (which had reappeared at 1 PM). When I checked at 2:55 PM, the magic green 110k appeared. Shamrock green! It was my lucky day.

I phoned United, got right through, and spent the 40k miles I had topped off in my Mileage Plus account from Chase UR 2 days earlier. I told the phone agent I'd like a fee waiver due to having paid a fee the preceding day but it wasn't a deal breaker. He waived the fee and I thanked him profusely. I got 4 my F seat 23.9 hours before departure.

From my observations of available seat counts for cash and awards, I believe Lufthansa is using approximately the following algorithm on its West Coast to FRA routes:
- Business class award seats are released if the unsold count is >2 one day before departure, >4 two days before departure, and >6 three days before departure.
- First class award seats are released if the unsold count is >2 one day before departure, and possibly if the unsold count is >3 two or three days before departure (seen early in August but I didn't check unsold seat count)

I am so looking forward to this trip. My 5 hour connection will fly by in the FCT. Thanks to everyone here.