SchemaDiffTool: schema sync script error when changing output data type or OUT argument list in function

Changing the output data type or OUT argument list in the source schema function causes the target schema synchronization script to fail. This change is not considered an overload in PostgreSQL and cannot be applied until the function is removed.
Problem reproduction:
Scheme source:

CREATE OR REPLACE FUNCTION class_del(
	iid bigint)
    RETURNS void
    LANGUAGE 'plpgsql'
    COST 100
    VOLATILE SECURITY DEFINER PARALLEL UNSAFE
AS $BODY$
    --source FUNCTION new API 
DECLARE
    action_state character varying DEFAULT 'none';
BEGIN
    ---Code Function
	--************************************************************
	----------------THROW EXCEPTION
	--************************************************************
	IF (action_state <> 'action_allowed') THEN
		RAISE EXCEPTION 'Error message';
	END IF;	
END;
$BODY$;

Scheme target:

CREATE OR REPLACE FUNCTION class_del(
	iid bigint,
	OUT Result INT)
    RETURNS INT
    LANGUAGE 'plpgsql'
    COST 100
    VOLATILE SECURITY DEFINER PARALLEL UNSAFE
AS $BODY$
    --target FUNCTION old API 
DECLARE
    action_state character varying DEFAULT 'none';
BEGIN
	Result = 0;
    ---Code Function
	--************************************************************
	----------------THROW EXCEPTION
	--************************************************************
	IF (action_state <> 'action_allowed') THEN
		Result = 144; --Set error code
	END IF;	
END;
$BODY$;

PS:
I do not think that this can be separated into a separate topic. I want to draw your attention to the fact that the state of the selection filter does not affect the script generator in any way and has a purely cosmetic (ostentatious) use. If this behavior could be controlled, the severity of the problem would decrease. I have more than 700 functions in the API and I can only edit the full script in third-party editors, since yours just freezes (on my computer). Applying a filter would allow me to step-by-step sync by changing the accepted sync strategy.

Start with the SchemaDiffTool script generator and reproduce the failure using the source and target function definitions in the issue, changing the return type or adding an OUT argument. Trace how function differences become synchronization statements; done means the generated script can apply this change without manual removal, and investigate whether the selection filter affects generation as a separate concern.