ENH: _check_user_input method being called multiple times

[lucasfourier]

Describe the bug

The _check_user_input method is being called multiple times for some unexpected reason during init for the same source file.

Expected behavior

Processing should not result in redundant calculations and function calls.

Additional context

This discussion arised from a hotfix. For additional information, one should read the following: #478

[Gui-FernandesBR]

I'm not sure if this is a bug, it was exactly what was intended.
An optimization is more than welcome tho, calling it multiple times is a bad idea.

[lucasfourier]

True. Changing the label.