I came across your string of messages just after writing to my former Turkish teacher on this subject. May I cut and paste?
While editing a legal handbook, I was confronted a few times with a "whilst" that didn't sound right to my ear. After a little reseach, I learned that the "-st" suffix in whilst, aidst and amongst is an "excrescent suffix"; according to my dictionary, excrescent means "of a sound in a word growing out of ['crescent' from the French 'croissant', growing (not to be confused with the breakfast roll, except indirectly though Marie Antoinette, the defeat of the Turkish army, the moon as a symbol of Islam and the moon in its "rising" (cresent) phase, but that's another story)] the action of the speech organs in forming neighboring sounds".
Now I had always thought that sound changes in suffixes were limited to Turkish, but here it is in English. The -st is added when the next word begins with a vowel, similar to "an orange" as opposed to "a pear" and the French liaison, where you pronounce the last letter of a word if the next word begins with a vowel, as in "pas encore", where there is a "z" sound between the two words, at least in my neighborhood.
So proper English usage calls for (or called for, perhaps some long time ago) whilst, aidst and amongst when the next work begins with a vowel. "Amongst us" but "among those present" ... it's just easier to pronounce.
As an American, I won't be using whilst any time soon, but I'll stop correcting my English colleagues who do, depending on the first letter of the next word, just to be pedantic.