@vmedea It didn’t. I am wondering whether the correct nm parameter is dhcp-client-id (not dhcp-hostname) so I changed that one as well and we will see tomorrow.
As you can see from the side discussion that I am having with @vmedea this is a can of worms but …
The actual hostname is permanently stored in /etc/hostname but on the other hand you can theoretically change the hostname temporarily (which may be what you want here) using the hostname command.
The problem in the previous paragraph is that some random software might just read /etc/hostname so there is definitely an element of trial and error.
One approach would be to change your hostname permanently to some long, random, unique, printable, valid string, then change it temporarily to another long, random, unique, printable, valid string - and then go looking for all the places on or coming out of your own computer that either string shows up. Then work out how that place got hold of the hostname.
That will give you an inventory to work on.
Only then would you go ahead and implement actual hostname randomization.
You may have to adjust /etc/hosts as well.
As you can see from my side discussion about DHCP, that is just one of the places where the hostname can be independently configured. If you don’t use DHCP then you can bypass having to think about that but then for a portable device you more or less do want to use DHCP.
As far as I know the browser does not transmit the hostname in the User-Agent string. It does however transmit the operating system and version (which is itself bad enough) unless you take action against that.
I would like to state for the record that there is no way that I would want hostname randomization and there is no way that I would want to set the hostname to “linux” (or similar) on all hosts. I have many hosts and I need a sensible, unique name on each host. Your mileage is free to vary. 