The "SXCU Import" option takes file path as a text, instead of using some form of file picker. This is not very user-friendly for obvious reasons and is very inconvenient, even if it's only meant to be used once.

I have been notified of an LWJGL library called "tinyfd" which can be used to create a platform independent file dialog. The system can be migrated to this in the next version of Screencapper.