Ron,
Yes, the 2nd pass begins, just like the first, with the focuser moving out and then back in to try to remove backlash. You should be able to see the focuser movements in the logs, or in the log box at the bottom of the Focuser Tab.
There is quite a bit of noise in the HFR calculations for reasons I don't full understand. Perhaps it's seeing, perhaps it's image noise affecting the star extraction scheme, etc. I had hoped my scheme to use the same stars to compare images would remove all that, but when I was testing that change, as I recall, I found some improvement, but I believe the majority of the "HFR noise" remained.
More detail on the first point. I just ran Linear autofocus using the simulator profile, and below are the lines in that log box at the bottom of the Focus Tab. I've highlighted in red lines at the start of the first and 2nd passes that show the focuser moving out then back in.
Hy
2022-01-23T13:01:29 Focus procedure completed after 19 iterations.
2022-01-23T13:01:29 Detection complete.
2022-01-23T13:01:29 Detecting sources...
2022-01-23T13:01:29 Image received.
2022-01-23T13:01:27 Capturing image...
2022-01-23T13:01:24 Detection complete.
2022-01-23T13:01:24 Detecting sources...
2022-01-23T13:01:24 Image received.
2022-01-23T13:01:22 Capturing image...
2022-01-23T13:01:19 Focusing inward by 500 steps...
2022-01-23T13:01:19 Detection complete.
2022-01-23T13:01:19 Detecting sources...
2022-01-23T13:01:19 Image received.
2022-01-23T13:01:17 Capturing image...
2022-01-23T13:01:14 Focusing inward by 1,000 steps...
2022-01-23T13:01:14 Detection complete.
2022-01-23T13:01:14 Detecting sources...
2022-01-23T13:01:14 Image received.
2022-01-23T13:01:12 Capturing image...
2022-01-23T13:01:08 Focusing inward by 1,000 steps...
2022-01-23T13:01:08 Detection complete.
2022-01-23T13:01:08 Detecting sources...
2022-01-23T13:01:08 Image received.
2022-01-23T13:01:06 Capturing image...
2022-01-23T13:01:03 Focusing inward by 1,000 steps...
2022-01-23T13:01:03 Detection complete.
2022-01-23T13:01:03 Detecting sources...
2022-01-23T13:01:03 Image received.
2022-01-23T13:01:01 Capturing image...
2022-01-23T13:00:58 Focusing inward by 1,000 steps...
2022-01-23T13:00:58 Detection complete.
2022-01-23T13:00:58 Detecting sources...
2022-01-23T13:00:58 Image received.
2022-01-23T13:00:56 Capturing image...
2022-01-23T13:00:52 Focusing inward by 10,000 steps...
2022-01-23T13:00:49 Focusing outward by 20,923 steps...
2022-01-23T13:00:49 Detection complete.
2022-01-23T13:00:49 Detecting sources...
2022-01-23T13:00:49 Image received.
2022-01-23T13:00:47 Capturing image...
2022-01-23T13:00:44 Focusing inward by 2,000 steps...
2022-01-23T13:00:44 Detection complete.
2022-01-23T13:00:44 Detecting sources...
2022-01-23T13:00:44 Image received.
2022-01-23T13:00:42 Capturing image...
2022-01-23T13:00:38 Focusing inward by 2,000 steps...
2022-01-23T13:00:38 Detection complete.
2022-01-23T13:00:38 Detecting sources...
2022-01-23T13:00:38 Image received.
2022-01-23T13:00:36 Capturing image...
2022-01-23T13:00:33 Focusing inward by 2,000 steps...
2022-01-23T13:00:33 Detection complete.
2022-01-23T13:00:33 Detecting sources...
2022-01-23T13:00:33 Image received.
2022-01-23T13:00:31 Capturing image...
2022-01-23T13:00:27 Focusing inward by 2,000 steps...
2022-01-23T13:00:27 Detection complete.
2022-01-23T13:00:27 Detecting sources...
2022-01-23T13:00:27 Image received.
2022-01-23T13:00:25 Capturing image...
2022-01-23T13:00:22 Focusing inward by 2,000 steps...
2022-01-23T13:00:22 Detection complete.
2022-01-23T13:00:22 Detecting sources...
2022-01-23T13:00:22 Image received.
2022-01-23T13:00:20 Capturing image...
2022-01-23T13:00:16 Focusing inward by 2,000 steps...
2022-01-23T13:00:16 Detection complete.
2022-01-23T13:00:16 Detecting sources...
2022-01-23T13:00:16 Image received.
2022-01-23T13:00:14 Capturing image...
2022-01-23T13:00:11 Focusing inward by 2,000 steps...
2022-01-23T13:00:11 Detection complete.
2022-01-23T13:00:11 Detecting sources...
2022-01-23T13:00:11 Image received.
2022-01-23T13:00:09 Capturing image...
2022-01-23T13:00:05 Focusing inward by 2,000 steps...
2022-01-23T13:00:05 Detection complete.
2022-01-23T13:00:05 Detecting sources...
2022-01-23T13:00:05 Image received.
2022-01-23T13:00:03 Capturing image...
2022-01-23T13:00:00 Focusing inward by 2,000 steps...
2022-01-23T13:00:00 Detection complete.
2022-01-23T13:00:00 Detecting sources...
2022-01-23T13:00:00 Image received.
2022-01-23T12:59:58 Capturing image...
2022-01-23T12:59:54 Focusing inward by 2,000 steps...
2022-01-23T12:59:54 Detection complete.
2022-01-23T12:59:54 Detecting sources...
2022-01-23T12:59:54 Image received.
2022-01-23T12:59:52 Capturing image...
2022-01-23T12:59:49 Focusing inward by 2,000 steps...
2022-01-23T12:59:49 Detection complete.
2022-01-23T12:59:49 Detecting sources...
2022-01-23T12:59:49 Image received.
2022-01-23T12:59:47 Capturing image...
2022-01-23T12:59:42 Focusing inward by 10,000 steps...
2022-01-23T12:59:41 Focusing outward by 12,000 steps...