User-friendliness vs. conformity (with an app)

I have two apps:

App #2 reads text files to display 3D objects with specific coordinates (e.g. a sphere, a cube, a pyramide and a cylinder) in a VR environment with each file having its own unique name. The main menu has buttons for a limited amount of objects you can choose from (1 button = 1 object). If there's only one text file, there's also only a single button.

App #1 is used to manage these objects: It lists the names of all existing files, lets you download new ones and delete old ones (there are a couple more features). It also lets you choose a specific file from its list and start up app #2 with it.

Now here's the hard part: If you have to choose between user-friendliness vs. conformity, what do you usually go for and why?

In my case: Let's say I choose a sphere in app #1 and click on the "display in app #2" button, what would you (a user of my app) expect to happen:

a) Instantly display the sphere (user-friendly because no "are you sure" "message") OR

b) show the main menu with just a single button for the sphere (conform with how my app works otherwise)

Are there any occassions when you should always choose user-friendliness over conformity (and vice versa)?