More is not better: I am not sure why you want to do more flexion postures in your practice. When I look at your flow you already do Butterfly (flexion), Half Butterfly (flexion), Caterpillar (flexion) and then you do Snail (more flexion!). Yes, you certainly can do the same pose twice with a break in between, but if you are thinking of doing another Caterpillar in this flow, then I would suggest dropping the Snail pose.
I might also suggest that after all your spine flexion and extension postures are done, you may want to finish with a short reclining twist to release any residual tensions along the spine, or move the Cat's tail to the end.
Sitting in meditation is a lot of constant flexion already for the hips and a bit for the lower back. You may not realize it but the lumbar does tend to flex when we sit for long periods. Going deeper into flexion as your practice does is not bad, but you may want to make sure you also spend equal time in extensions, twists and lateral flexions.
