If I replace blob by varchar, no issue (script at the end of this post)

So, I don't understand why it couldn't work also with blob, it's not logical.  Why blob are not released in this case, why keep blob id ?

SET TERM ^ ;

CREATE OR ALTER PROCEDURE BLOB_MEMORY_TEST2

RETURNS (

    B VARCHAR(1000))

AS

declare variable i integer;

begin

  i = 0;

  while (i < 15E6) do

  begin

    select b from BLOB_MEMORY2 into b;

    i = i+ 1;

    suspend;

  end

end^

CREATE OR ALTER PROCEDURE BLOB_MEMORY2

RETURNS (

    B VARCHAR(1000))

AS

begin

  /* Procedure Text */

  b = 'Test';

  suspend;

end^

SET TERM ; ^