It turns out, if you extract the game's NSP the files are nearly identical to those on the PC release.
This means you can use Layeredfs to get some of the PC mods working on switch, however this only works with XNB mods. This will not work with mods that use SMAPI or any other program that patches the game.
How to use:
Just place the files of your mod into atmosphere\titles\0100E65002BB8000\romfs\Content just as you would copy them into the content folder on the PC release.
And voila the new assets are loaded from the mod:
I have only tested custom portraits, but other mods should work as well. Use at your own risk, and make sure to back up your save data.
This means you can use Layeredfs to get some of the PC mods working on switch, however this only works with XNB mods. This will not work with mods that use SMAPI or any other program that patches the game.
How to use:
Just place the files of your mod into atmosphere\titles\0100E65002BB8000\romfs\Content just as you would copy them into the content folder on the PC release.
And voila the new assets are loaded from the mod:
I have only tested custom portraits, but other mods should work as well. Use at your own risk, and make sure to back up your save data.