I also really enjoyed Sidney. Watched the penultimate and finale the other day. You can cut the finale into 2 distinct acts: Hawkeye at the Psych Hospital and the Bug Out/wars end.
It's also interesting how they let BJ leave in a similar manner as Trapper (w/o saying goodbye). BJ's story also reminded me of Christopher Robin in the 2018 live action film being sent away from his wife and daughter who has no idea what he looks like. Unlike Christopher, BJ was able to hold Erin in his arms before being sent off where Christopher was drafted while his wife was still pregnant. Erin calling Radar "Daddy" has to be a priceless moment (at least in Universe).
The loss of the Chinese Musical POW's was very hard, I feel a little empathy for Winchester there.