It's not where I expected to find it, but you can change the mouse cursor to anything you want from here.
Just put your .theme files in ~/.icons and they'll show up in the "Cursor" dropdown.
The cursors I installed ("Hackneyed", as mentioned above) come in a scalable version that actually works in combination with the Cursor Size setting in Accessibility Settings, so I can have my large yellow cursor, finally.
(These settings are a bit all over the place? I personally would have put all mouse related settings in Settings -> Mouse and Touchpad, not scattered across three different screens in two different apps. I'm pretty sure people who need the mouse settings for accessibility reasons would also be able to find them in the mouse settings?)
Another minor annoyance is the cursor size settings in Accessibility settings aren't granular enough - it's likely monitor dependent, but my choices were "Medium", which is too small, or "Large", which is 2x that and way too large.
I discovered the "Dconf editor" which lets you set any size in pixels:
(Once again, finding this in Software gives you two results, a current Flatpak and a Zorin OS package that hasn't been updated in 2 years. This is starting to look like a pattern. Why is the first option always an outdated Zorin OS package? The packages look 100% identical in the search results. This result really needs to be a table showing the source and release dates.)
(And why wouldn't you just have a pixel value input or slider in the cursor size configuration screen, below the preset sizes? Weird.)
Anyhow, problem solved, just thought I'd share the solution.
I thought I knew what LTS meant, so forgive me if this question is dumb...
But Zorin 18 was just released - aren't feature updates supposed to come with major releases? When else would you get major updates to various software components?
And not a single one of these apps have received any bug fixes or security updates in over two years, really? I haven't checked, but I'd be a little surprised. With so many updates, surely some of them were bug fixes, yes?
What it looks like to me is nobody's maintaining that repository?
Here would be the Question how the 2 Years are related. It could be that it stands for the initial Version that came in the Repo's but not the actual last Update.
Well, here You have to seperate 2 Things: The Zorin 18 Release and the Ubuntu 24 LTS Release which is the Base of Zorin 18. This Base - and so the Softeware in the Repo's of it - are older.