Are you saying the Jews were right to refer to God as Adonai so they wouldn't misuse his name?
How brilliant they were, what a great idea.
So if I avoid the use of yah I'll never profane his name, right?
Nope. Not at all. In fact jews were wrong idolatrous (false worship) to not pronounce or write His name whenever appropriate.
Writing His name on a perishable paper is no offense or taking it in vain. Taking His name in vain is literally carrying it written in stone from Sinai to Jerusalem and still living NOT in accordance to His Will, after Him His way...bringing worship and honor and glory for all He did/does for His people...that is taking His name in vain...or having it for naught
Avoid using Yah and you'll struggle saying HalleluYah or IsaiYah, or JeremiYah or EliYah etc.
Or saying the name of His Son...
The Septuagint translaters too may have followed with some agenda to make scripture more palatable for non jewish readers.