I have never had to use anything like pre-load in my shifting! Downshift on any bikes should never be a problem, and if it is, I think that you need to find an old-timer to show you how to "rev-match". I never even knew that's what it's called until recent years, but that's how every riders that I knew downshift on a bike when I started riding in the '60s!
The wetheads "can" have clunky upshifts, especially in lower gears, and at low speed and acceleration, BUT it is possible to get noiseless shifts, once your bike is broken in "properly", like mine, and you also have to learn some techniques (beside pre-loading) for noiseless and smooth shifting at low speed. I guess the only place where I think pre-loading can be handy is when you shift from neutral to 1st, BUT then my bike is never in neutral when I ride, and it's always parked in 1st, which is another old habit! I can never understand why any one would park in neutral, but there are several reasons why one should always park in 1st!
Want to hear noiseless shifting? Watch this video of the highlight of one of my recent ride, on my '15 RT. The microphone is attached to the front of my jacket, about 1/2 way down, and so the audio is everything that one would hear from the bike. Watch on a desktop computer, otherwise the audio is likely to sound a little tinny!https://youtu.be/npl0LeYQpj4