Another interesting thing that I saw a short while ago in הישיבה הרמה בפיורדא (volume II, p.60).
It states that the name הירש, which is the vernacular כינוי and translation of the popular Hebrew name צבי, was actually pronounced in אשכנז as Harsh (or Harsch), as if there was a פתח under the ה. The חתם סופר felt strongly about this and stated as much. One can see in many places in his writings, in accordance with this, that he spells the name הרש, without a yud, which he felt (inclusion of) led people to pronounce it incorrectly. However, he states that in Poland, it was pronounced Hirsh (Hirsch), with a חיריק.
And nowadays there are others who pronounce it Hersh (Hersch) as well – as if the spelling was הערש, which one actually can see too. I am referring to those whose pronunciation is to say lecht instead of licht, e.g. in the term ליכט בענטשען/צינדען
That is just one elaborate example of a nice amount of material in הישיבה הרמה בפיורדא related to onomastics in general, and Jewish onomastics in particular. The author frequently uses נקודות to help the reader handle obscure and extinct names that come up in the narrative, which likely are not familiar to them.