Sorry I left this thread hanging for a while. It's been weird times.
First of all, thank you
@faj for your very detailed and thoughtful comments. Somewhat opposite to you, until fairly recently, I was only drinking japanese greens (in very diverse japanese teaware). Then I started getting into Chinese greens and now I'm full-on (and all over the place) with oolongs, blacks and puerhs. That's why these days I am only brewing the occasional hojicha and maybe a green or two that comes in taster sizes because like you I try not to leave already-opened bags of greens hanging out for too long in my cupboard or fridge. (Btw, I am deeply curious about the japanese teaware and teas you've been combining them with. Could be an entire thread in the Japanese section, but please do feel free to share if you have the time and inclination. I'm particularly partial to hearing about the Kobiwako, since I've been considering adding one to my collection. And would you mind telling me what kind of modern yixing you ended up getting?)
So now a more general update: I've continued to do a bit of testing during this down time. I first reduced each test to 3 teapots tops because more was too overwhelming. Sometimes I only used 2. The way I do it is brew in a gaiwan and then pour into the yixings, leave it for 10-15 seconds and then pour into cups. With this method it's been easier to identify the clays that clearly DON'T work at all with some of the teas I drink more often, than the ones that are a perfect match. Perhaps, except for the zhuni and the hongni when tasting fruity green oolongs. Every other pot flattened them too much, so first conclusion is for zhuni and hongni for gaoshan and tgy (though my zhuni also works pretty well for yancha, some shengs, oriental beauty, a winter dancong, and a couple of blacks...) and the duanni for one particular floral green oolong.
So far this is what I got. What I've sort of narrowed down (just a bit) by brewing in porcelain and pouring into the pots:
-ZHUNI (wendan): nothing a big no, but especially good for gaoshan, tgy, yancha, dan cong, oriental beauty, sheng, fujian hong cha
-HONGNI (ju lei): works with pretty much everything, but especially with gaoshan, tgy, dan congs, yancha, dark oolongs, hongcha,
-JIANGPONI (fei yun): tricky clay. So far, dark high roast oolongs, smoky hong chas, funky shengs seem to work well.
-DICAOQING (sangbian): particularly great for a heicha I just got, puerhs, hong cha, dark oolongs, aged white and some shengs
-ZINI (xiang yu): dark oolongs (especially rolled Taiwanese and yancha), shou, hong cha
-wood fired DUANNI (long dan): sheng, shou, heicha, and teas that are too smoky or funky. It also made one particularly floral oolong that is normal too much for me much more drinkable.
-ZINI (shi diao ti liang) : shou, heicha, yunnan hong cha, and dark oolongs
-HEI LIAO (li xing) : shou, heicha, hong cha, aged white, dark oolongs
-MANTIANXING (xi shi): shou, heicha, aged white
Next step is concentrating more in brewing in the pots with different parameters to see how shape and size affect the tea. I think I will try your "disciplined trial-and-error" method,
@faj and choose one tea and one of the pots that made it through and start. (Btw, love to read more about your note-taking. Do you have a notebook? How detailed are you? Again, this is not asking for advice, but about wanting to learn about people's different methods, procedures, modes of playing. I guess for inspiration, mainly.)