test RPGLE call with Run SQL Scripts

Some may find this intersting (maybe not).
I needed to test a vendor RPGLE program call. No access to the source code. Usually I would just write a small CLP and run in debug to check the values of the parameters returned.
Thought I would try testing with Run SQL Scripts:

Create or Replace Procedure mylib/RPPIB150
(InOut PITYPE Char(10),
InOut PIDATA Char(512))
Language RPGLE Parameter Style General
Dynamic Result Sets 0
External Name prodlib/RPPIB150;
Create or Replace Variable PITYPE Char(10);
Create or Replace Variable PIDATA Char(512);
Set PITYPE = 'KI740 ';
Set PIDATA = 'KI740C 1 RESNET 201508190800000000003851234000000000 ';
Call mylib/RPPIB150(PITYPE, PIDATA);
Select PITYPE, PIDATA From (Values (1)) as Col(N);
Drop Procedure mylib/RPPIB150;

This works well, it would be nice if the SP parameters defaulted to INOUT instead of IN, then I would not need to create/drop the external stored procedure definition.
You can call RPGLE programs as stored procedures using the RPGLE name without creating the SP, but SP parameters default to IN only, unlike RPGLE.
Probably just as easy to write the CLP and call in debug mode.
Is there a better way to unit test programs without source code and debug data?