Ironically my circa 1995 Sony Trinitron CRT failed some of the tweak16b modes. I certainly wasn't expecting that!

I think you should restrict submissions to a particularly known excellent VGA card (such as those that show up on http://gona.mactar.hu/DOS_TESTS/
or else you'll have too many variables?

^^ Meh, that seems needlessly restrictive, not everyone has an exhaustive collection of VGA cards to choose exactly the right one from (least of all me) and that would prevent running from laptops. Most of the apps I included should run on any reasonably compliant VGA, Copper & Dowhackado being the main wildcards. Really I'm not aiming for a full scientifically rigorous dataset, just a bunch of useful info/hints for DOS enthusiasts who might be trying to choose a monitor. 😉

I thought of adding CGA composite, which is rather non-standard and can be problematic to run, but I imagine the amount of people who have a CGA card *and* a dual-scan VGA/NTSC monitor they want to test is a bit limited. (I don't have a CGA myself.)