When I did the search there were fewer than 20 results between them 180 vs 160 or something. Anyway, you can try other words and examples.
I don’t get your distinction and what are words that “contain yiddish vowels”? Every word can be written with “yiddish” vowels.
The suffix thing shown that sometimes the vowels are left out when it doesn’t add. There are better examples no doubt.
I am making up rules based on experience not formal knowledge of grammar, but I suspect that your “yiddish vowels” rule is similarly made up. True?