I fixed my recurrent back pain with a 6 mn daily morning, ie. plank, side plank, reverse plank, 1mn 30 sec each.

Posture muscles are not very well known in the general public. Loss of strength due to aging and sedentary lifestyle makes standing, seating, etc uncomfortable.

The best posture is your next posture.

I'd say as long as you use all your muscles meaningfully everyday, and don't spend hours in a single position, you're good.