Most people are using afterburner's monitoring graphs during overclocking since their clock controls are right next to them. Seems redundant needing to open another monitoring program to run your artifact test. Now if he added overclocking support to gpu-z that'd be a more appealing package.
In general nobody seems to want to develop a stability test for gpus these days. Everything out now is old and inaccurate. Either it's very hard to stress a modern gpu properly or nobody wants to put in the effort, because right now even OCCT doesn't stress as accurately as 99 loops of the crysis benchmark tool.