In T62928, keyboard shortcuts were implemented for WikiEditor. These are currently available when WikiEditor is used by itself or with CodeMirror 5. CodeMirror 6 support is missing.
Conflicts with CM6 keymap need to be checked. Notably, the shortcut for italic (Ctrl-i) clashes with CodeMirror's selectParentSyntax action – which for wikitext appears to be equivalent to "select all".