@daas yochid-
I am aware of those things (I read the teshuva). What you are saying has no relevance to whether it’s a kula or a chumra. He kept CY: probably because he wanted to be machmir. He recommends a baal nefesh keep CY yes, because he thinks a baal nefesh should be machmir.
I am aware that other poskim do not agree, but…
@newhere-
Kula is the WRONG term, not only not the best term. It’s my pet peeve because when I was in elementary school the boys who didn’t keep cholov yisroel were made fun of for being mekel and I thought that they were factually correct (though had disgusting middos), than in beis midrash I learned the teshuva, and I found out that it’s not true at all.
As for eruvs, notice how you both used most eruvs, and almost all eruvs. That is not the concept of eruv. I’m no expert in eruvin, but I’m pretty sure that everyone agrees to the concept, seeing as there is a whole mesechta in shas about it.