I completely disagree with this, and hold it to be nonsense.
Clear, smooth, intelligent writing is possible, even with saltations. Some continuity is good, but absolute, mathematically rigorous, piecewise continuity is only a pointless obsession. I agree with snoe on the rule of three; I agree with nearly all snoe said.
In American English, periods and commas are placed inside the quotation marks. It’s surprising that a gentleman of your age and pedagogical inclination wouldn’t know that.
A gentleman of my age has done plenty of writing outside the purview of American English. But I’m glad you had the leisure to carefully searcy my entire post until you finally found an Americanism that you can quibble with.
It is interesting to read the history of why the American publishers deviated on that style-guide issue. To save you the trouble, it is because the period outside the quotation marks (where it logically belongs) often broke off the printing plate, so they decided to put it inside, not as a style issue, but as a mechanical one. Which I don’t consider to be relevant in on-screen typing, so I leave it where it belongs, as a part of the statement that it complements.
I’m not sure what you mean by “searcy” your post. Are you referring to Searcy, Arkansas, which—as I’m sure you know— is the largest city and county seat of White County, Arkansas, United States? It’s interesting to note that according to 2014 Census Bureau estimates, the population of the city is 23,768, and that it is the principal city of the Searcy, AR Micropolitan Statistical Area which encompasses all of White County. Also of historical significance is that the city takes its name from Richard Searcy, a judge for the Superior Court of the Arkansas Territory. A college town, as you are doubtlessly aware, Searcy is the home of Harding University. Or did you simply mistype the word “search”?