The indent table's docstring says what a with- and a qualified head do

emacs/flan-mode.el

@@ -581,8 +581,9 @@ For `syntax-propertize-function'."
     ("declare" . 1)
     ("declare-c" . 1))
   "How each form indents, by name.
-Anything not named here that begins with `def' is treated as `:defn' by
-`flan-indent-function'; anything else indents as a function call.")
+A qualified name falls back to the entry for its unqualified part.  Anything
+still unnamed that begins with `def' (but not `default') or `with-' indents as
+`:defn' in `flan-indent-function'; anything else indents as a function call.")
 
 (defun flan--indent-spec (name)
   "The indent spec for the form called NAME, or nil.