I use Blender 3D for both 3D Printing and 3D Animations. I created a startup.blend file for 3D printing, that is perfect for my printer bed, and added a bunch of 3D printing related add-ons, removed the camera and lights.
For my work, I also do a bit of 3D animations for clients. When doing the animations, I always start with my custom startup.blend file, but then I have to go in a add lights, camera, etc to setup for my animations.
I have modified the blender "New" file menu (and the New file startup screen) by modifying Blender.app (MacOS). I did this by duplicating the VFX folder located at:
/Applications/Blender.app/Contents/Resources/3.3/scripts/startup/bl_app_templates_system/VFX
... I called it 3D_Printing, and editing the files. Now I have this option in both places.
My solution is going to be wiped out when I update Blender and will have to do this all over again.
My question is, is there an easier way, or an official way of doing this?
Edit/Answer:
Based on the comments, it looks like you create a Template! For macOS, I did this:
Created "startup" folder in the /Users/dougjones/Library/Application Support/Blender/3.3/scripts directory.
Inside "startup" created these directories: /startup/bl_app_templates_user/
I moved my "3D_Printing" directory in there, and everything is working as it should!

