I added a trustall command in latest build but I may have forgotten to test admin claims I'll test it tomorrow.
PEX is no longer being maintained. Migrate to LuckPerms to fix that issue.
By using the /cfg command. Read the flags section on wikI.
SpongeAPI doesn't support it at the moment but I'm working on my own implementation which should be available soon.
Update to latest SpongeForge, GP and LP.