Custom profiles are usually small files with a .3dsen extension.
If your interest is piqued, here is your treasure map: 3dsen profiles
If you find a new profile (usually a .3dn file) from a source like the 3dSen Maker Itch.io forums, follow these steps to use it: Custom profiles are usually small files with a
3dSen profiles (or files) are the custom data sets that allow the emulator to transform flat 2D NES ROMs into interactive 3D environments on the fly. 3dsen profiles