Metasequoia GENERALLY seems to break dormancy earlier and go dormant later than Taxodium D. here.

Helps lead to faster growth at the risk of frost damage.

FWIW my metasequia has hints of fall now a zone colder than you though.

Do you have both in your yard? I have metasequoia and metasequoia ogon and there are plenty of taxodium in the local parks.

Yes, I have both in the back. This is the first year though, that I noticed this difference in Fall coloration. One plus over Taxodium, in my opinion. No Autumn color change at all on the DR at this point. Fairly mild but we need rain. Semi-drought now developing in some Eastern zone.

I don't know about the Taxodium but our DR has no sign whatsoever of autumn. It's been really mild here though but it is one of our last trees to get its colors.

Dawn redwood still solid green here. Bald cypresses mostly green -- some just beginning to change. The final result is similar -- nice bronzy-red.