Did some thinking about this- Here's something no one has every ...thought of it seems-

Right now, from a steganography standpoint, there's no real way to be secure from this sort of thing. US Customs, or another country , from a tech standpoint. Yes, the cloud, though not everyone will have resources to access enough space online to keep their data secure - or be able to properly make a usable copy or image of their device that includes every aspect of their device, for a complete , fully restore later

-Why aren't there more plausible deniable, or just, stealthy encryption options? It appears, there's nearly NONE today for these advanced used cases.

Veracrypt is known for it's hidden features -but those are ...dangerously approaching obsolescence. Their Hidden OS option- ONLY works if you've formatted your system to MBR, not UEFI- otherwise you can't use the Hidden OS option.
Are you telling me for every laptop you buy form here on out, you'll format it to the old MBR standard to use the Hidden OS option for your personal laptop that you want to take on a trip- or need to?

And sure, you can just put important data in Hidden Volumes as a fallback- but then you come to a common fight today in the tech world of system vs file level encryption. And sure, just hiding what is most crucial, is perhaps better form a standpoint of sneaking by- but is it truly now impossible to hide everything else that's not as important, by default? Furthermore, you have to wipe traces of the material's location where it was BEFORE you copied it into the hidden volume. Did you also eliminate all traces? Windows Shellbags are a thing, that nearly no one knows will be a smoking gun..

Veracrypt doesn't work on Mac or Linux with it's Hidden OS option, just volumes.

There was a really promising advanced system being built - here, and it was even presented at a blackhat conference i think
https://portswigger.net/daily-swig/russian-doll-steganograph...

https://i.blackhat.com/eu-18/Thu-Dec-6/eu-18-Schaub-Perfectl...

But i've heard nothing since- and right now, all your data will be at risk from your computers ,phones ,and tablets, when you go through Customs- even if it's encrypted, they'll hang on to it, and image and copy the data. If you refuse to provide encryption passwords, they'll potentially keep it and not return it to you in all cases. This is where the deniable systems would come into play- where you'd be okay, if they just unlock it. Now if they plug it in and image it regardless, you're at risk because theoretically they could be running exploits on your device(they won't let you watch them imaging it so you can'tverify that ever)

-encrypted data will be unreadable here, but it's not as good as if they can't tell it's hidden, from a imaging point when they plug in a Cellebrite or Greykey device and have it run it's exploits to get everything.

And i do not see the Forensic Security community often giving recommendations on what it takes to get around this, i think this leads to the public being at the mercy of officials-

This will become very destructive also, as this will become a precedent. Imagine Southern States checking devices like to look for evidence of abortion information-searches, for example. Imagine Abortion getting federally banned, and then customs checking for mentions of abortion .

- Technical solutions aren't a full solution, as the EFF loves to hamper on- but it appears everyone has given up with efforts to even provide them.
I suppose if you want to stand a chance, you need to go become a expert on disks, and forensic techniques , in order to then even have a chance at experimenting on how to get around that- and if that sort of privacy ,security, and plausible deniability cannot be brought to the masses at large, the way Signal did for encrypted communications, ...