Teiid stored procedure command or assignment statements do not typically make use of inout/out/return values (the exception is if a resultset is not returned). It would be better to allow variables to be used in inout/out positions to capture the out values.

e.g. instead of

call proc(1)

just implicitly creating the result set to return,

a = call proc(1, b)

would also assign the return value to a and would set an out value to b.