move Home folder location - issue

Here is an Apple article with instructions for how to change the name of a macOS user folder/account...the same instructions apply when pointing it to another volume, although you must perform a few other steps as well which are not noted in this article. If you attempt this, then make sure to leave the other admin user account on the boot drive so you can at least operate the Mac if something goes wrong later on. Be prepared to deal with possible issues later on though...can you afford to deal with this setup breaking even for a few hours?

Change the name of your macOS user account and home folder - Apple Support

However, beginning with macOS 12.5.1 update, macOS kept breaking things for users who placed their home folders on another drive. I have no idea whether macOS was ever fixed to not break this setup, but I personally would not trust such a custom setup. macOS does not like it when people deviate from the system defaults for such a major feature. I have seen macOS complain about much simpler changes than the one you are proposing.

https://discussions.apple.com/thread/254143123

Besides that previously known issue, you may also encounter another newer issue which could break such a setup. There have been a lot of recent reports of users having their external drives disconnect without warning. This would be a major issue if your macOS user account is on an external drive and it disconnects. Not really sure on the reasons, but it almost seems like there may be a new macOS bug out there, but unfortunately not reliable information or details have been provided to be certain, although something is obviously happening to many users' external drives.

You would be better served by just placing the large files on external media. There have been instructions on these forums for moving just the Picture/Photos to external media if that is the only item requiring large amounts of data.

Michel Corbin wrote:

I have copied my Home folder (and sub folders) to an external hard drive. I have followed the steps in settings -> users & groups -> advanced options -> choose to tell the system where I want it to find the home folder. It all goes well until I get the dialogue box below. I click Ok but nothing happens (the button does give a visual clue that it registered the click).

This is on a Mac Mini M2 on macOS Ventura 13.2.1

https://discussions.apple.com/content/attachment/f94c111b-8ce4-4245-b77a-d304ef76b88d

Yea... not advised to move the home folder.

Michel Corbin wrote:

Thank you for the thorough response. I realise it’s best not to fool around with Apple’s structure. I will create short cuts inside the key folders (Pictures, Movies, Documents) to point to the external drive.

That's not going to work.

If your data doesn't fit on your external hard drive, the only official, and well-supported solution is heavy use of iCloud with "optimize" settings enabled. Even then, I strongly advise having one machine that does not have any optimizations set so that it can download and backup the entirety of your data. This will require a monthly iCloud fee and also perhaps the cost of another computer/hard drive to keep the data downloaded and backed-up.

Failing that, having your entire home directory on an external drive is the next-best solution. Nothing that HWTech said is wrong, but this is a solution that should be expected to work. The key is that you can't expect this to work and also expect to always be on the bleeding edge of any software update. To be clear, anyone currently running any version of macOS Ventura is on this "bleeding edge". Back in those 12.5.1 days, macOS Monterey was that bleeding edge. Anyone who valued their data in any way would have been running Big Sur back then.

Currently, it is very unlikely that Apple would make any change to Monterey significant enough to break a home directory on an external volume. But in any event, moving your home directory to an external volume is an advanced option. You can expect regular problems, especially with 3rd party software. You also have to be careful about mounting the external volume. Either manually specify the mount point and/or make sure to enable ownership on the volume. This isn't normally done, so you are on your own in such a configuration. Don't attempt it unless you are confident in your abilities to correct any problems on your own.

But in spite of all of these complications, any attempt to use aliases, links, etc. is a guaranteed, hard fail. These will not work and will only corrupt your data.