[spaghettifythis]

Not op, but I often do say 'whilst' out loud. It feels more structured and certain than 'while', which feels floppier as a word.

[skinfaxi]

It's to be used when the word that follows begins with a vowel sound.

[moi2388]

Is it? Do you have a source for this? Afaik ‘while’ is often used in US English and ‘whilst’ in British English.

[finghin]

both are definitely used in modern British English, but whilst is strange to my ears as I grew up in Ireland