I only add water to stronger whisky (if I find it a bit "harsh" on first tasting), it can open up different flavours, but if overdone just makes the drink bland.
Your post made me look it up, this is quite interesting (although I don't believe the solubility bit - surely insoluble material would make the whisky hazy/fall out of the solution?)
I'm sure Grant will have a good idea what is going on :)
https://blog.scotchwhiskyexperience....ter-to-whisky/