Today I learned about "epenthetic schwas"

I've seen several online articles recently about the grammatically correct way to write the plural or possessive forms of names like Harris and Walz...

It all felt a bit, as some social media users described, like apostrophe hell: Would it be Ms. Harris’s and Mr. Walz’s or Ms. Harris’ and Mr. Walz’s? The Harrises and the Walzes? The Harrises’ family home and the Walzes’ family dog? It was enough to see double, made worse by the fact that stylebooks, large news organizations and grammar geeks were all split or contradicted one another.

Discussion continues at the source, but to me the only interesting part was this:

People can easily pronounce the plural or possessive of Harris or Walz, both of which contain epenthetic schwas, Ms. Holliday said. When a word ends in an S or Z sound, we insert a schwa — the “uh”-like sound that can be represented by any vowel in the English alphabet — to break up a block of consonants.

So, like Moliere's Monsieur Jourdain who discovered that he had been speaking prose for forty years without knowing it, I now realize that I've been using epenthetic schwas all my life! 

[epenthetic = inserted into a word].

See also Any vowel can become a schwa (2020)