I'm relieved to see my coflake beauty's condition improving, with significantly fewer white spots visible today. The fact that no other fish appear to be affected is a positive sign, and I'm cautiously optimistic about the situation.
I must admit, I'm still hesitant about setting up a QT tank, not due to the cost, but rather the daunting task of dismantling my display tank to catch the affected fish. I'm not sure I have the stomach for such a drastic measure.