Preparing to rig a helmet with a larger range of movement

[outer oasis]

;o; too many attachments, ill try again

Hello! I am currently preparing to rig a complex, full-head helmet for a client. I've done a few experiments, but am looking for advice on how to create a helmet that has convincing 3d movement. I usually do a 45 degree head angle for my models, and don't want this helmet to be any different if possible.

I've attached a video of my experimentation so far, which shows how I've kiiinda got the beginnings of the front parts head turn, but I feel lost when it comes to adding the sides. The sides hae some parts that jutt out, or only become visible when the head is turned.

I'll also send through some sketches of the head from other angles, as well as some 3d model references of a similar-ish helmet to get an idea of what I'm trying to achieve!
Any splitting guides, rigging guides, breakdowns, live2d tips or video references are greatly appreciated, thank you!

Here are the sketches (they're mainly just doodles, but show how there is stuffs on the side that is only visible or prominent from the side)