As a day-to-day user of UB 24.04, I hadn’t noticed it until now, but this option borrowed from Cinnamon seems to have disappeared since version 24.10, and will do so again in UB 25.04:
It’s very useful for recalibrating the grid and setting the distribution of icons on the desktop:
Could it be reinstated?
Well that option depends on this gsettings key nemo/libnemo-private/org.nemo.gschema.xml at 8d48119cd9b7fa1ec601294d7067905cb3338ebc · linuxmint/nemo · GitHub
Curious though what the nemo project means by “new style desktop” in the description
Thanks David, it’s the right key, but if it works on UB 24.04, it has no effect on 24.10 or 25.04: even if it’s set to “true”, the menu entry is not displayed.
I’ve found it: you first have to click on ‘Align to grid’ for the ‘Customise’ option to appear:
Not easy, Cinnamon-style.
I’ll rephrase the question: why not activate these two options by default?
If you find a way then let me know. Dont know myself how to-do
I found both the answer to your question and the solution to my request.
The key is org.nemo.dektop use-desktop-grid:
Summary : Which desktop view type to use
Description: If true, the new desktop grid view will be used by nemo-desktop, otherwise the legacy view will be used.
Its default value is “false” (“legacy” desktop grid):
It must be set to “true” to display the “Customise” option (“new” desktop grid):
gsettings set org.nemo.desktop use-desktop-grid true
It should therefore be set this way on installation.
It would also be more logical to place the “Customise” option just below “Align to grid” — but I don’t know how to do that (yet?). 
