☑ cool new feature
☑ could help many users!
☑ users can remove bugs on their on
☐ nice to have
☐ nobody needs it
What inspired this wish list request?
Via

a user can edit the main menu and [on windows systems] the toolbars.
Other menus cannot be edited.
Unfortunately, some of the implemented functions have bugs - and some functions are missing.
What is the improvement you would like to see?
Please add the possibility to remove items from any right click / red triangle / ... menu and the possibility to add user defined items.
This will allow us to fix tiny issues which won't make it into a future version of JMP - or just in many years.
e.g.
- Allow us to perform more actions when right clicking on column name on columns panel
- Paste Column has a bug and should be replaced with a version without bug: JMP jumps
Is it possible to customize the Add Formula Column menu to include customize functions?
yes and no:
- a user can not add user-Defined mini GUIs , e.g. to add Modulo to the portfolio.
- Existing functions cannot be added to the menu by name. (TS-00152405)
Why is this idea important?
Less pressure on JMP developers to bugfix and fine-tune the GUI. Users don't have to wait for version N+2.
-> Users will be able to bugfix and tweak the GUI on their own.
other wishes from 
All customizations (user or someone else has done) must be VERY clearly indicated in user's JMP menus or solving any issues user might have becomes a nightmare as the menus can be totally different. Most likely they should have to be able to access the "original" options by holding shift and opening menu or something similar.
Thank you for sharing this idea, and for the valuable feedback in the comments!