Grapheneos comment on hidden profiles/veracrypt style plausible deniability:
>It's possible to make a semi-hidden feature but hiding it well enough to avoid detection by software forensic tools requires not basing it around profiles. It would really need to be a nested GrapheneOS in a virtual machine. It could also still be detected at an SSD level
https://nitter.net/GrapheneOS/status/2081471477174456340#m
Here's some info from veracrypt on the SSD level.