> both its rotation and orbit are about 8 hours on the sameish axis. So
> it's still spinning pretty dang fast, enough that the gas doesn't have
> to settle into hot and cold sides.
Except that by spinning on the same axis [more correctly, on axes normal to the same plane] at the same rate the atmosphere is stationary in the co-rotating frame. That's what it means to be tidally locked. The gas is already divided into a hot side (always facing the star) and a cold side (always facing away).
> it's still spinning pretty dang fast, enough that the gas doesn't have
> to settle into hot and cold sides.
Except that by spinning on the same axis [more correctly, on axes normal to the same plane] at the same rate the atmosphere is stationary in the co-rotating frame. That's what it means to be tidally locked. The gas is already divided into a hot side (always facing the star) and a cold side (always facing away).