Cross-cutting concern-related options like debug (.e.g. --debug) and i18n currently have to be re-declared and dealt with for each subcommand. Picocli Issue #649 added a scope = ScopeType.INHERIT designation to allow options to be defined once and to take effect for subcommand.
Improve the BaseCliApplication to add these inherited options such as debug automatically.
Note that this functionality should have been released in Picocli 4.3, but because of Issue #1042 it looks like it will be fully ready in v4.3.1.