"Stress-Testing" a 2014 Mac Mini - without AHT Extended

[mad cow disease]

I just bought a 2014 Mac Mini off of eBay through a "new" seller, and it is out of warranty. I'd like to be able to put it through its paces, but without installing all kinds of software on it. In the days before Apple Diagnostics, I would just fire up Apple Hardware Test, put it on the extended run, and let it loop for 24-36 hours...if it crashed/failed within that period, well, I had my answer.

The "new & improved" Apple Diagnostics is not capable of this, it seems. Can anybody suggest a 3rd-party alternative?

 

[ActionableMango]

I don't know of any single piece of software that does it all.

Furmark for GPU stress test
Handbrake for CPU all cores stress test
Memtest86 for memory testing