Hi @JLU51306. The problem is that either LaunchBox or DIG sends the path of the game in an incorrect format, that doesn't coincide with the path waited in Dolphin (same with AetherSX2). So, until this isn't solved by the devs (already talked with @Jason Carr about this, he's pretty kind 😄) we do not have anything to do right now. For Dolphin, at the moment you can create some shortcuts with Shortcut Maker and Solid Explorer (all on Play Store) with the following data, it's not as great as LaunchBox, but works pretty well:
1- On Solid Explorer, search for the game image, long touch to it, three dots, properties, three dots again, and copy path
2- On Shortcut Maker, select Applications and search for Dolphin Emulator
3- Once selected, you can edit name, icon, and intent.
4- On the intent section, just select "Add extra" and fill it this way:
On KEY: AutoStartFile
On Value: paste the copied path and give the next format:
We have, for example, this path: /storage/emulated/0/games/wii/SM.iso
The Final Path must be this way: content://com.android.externalstorage.documents/tree/primary%3Agames%2Fwii/document/primary%3Agames%2Fwii%2FSM.iso
if you have spaces in the original path, you have to replace them with %20 and you have it. Hope this helps
PD: I'm not any kind of dev or worker, just a fan. Just in case