Different strokes , different folks
I don't find much difference between a clear or gold lacquered sax VS an unlacquered....there is some nuance slight difference in the tone colors. The lacquer on the antiqued/vintage finished P. Mauriats is IMO much thicker...and probably made used different substances than your pedestrian lacquer...and it does affect the tone to a greater degree. I think that is part of the reason for P. M's success in marketing a brand new horn that imparts a vintage horn vibe. It's also why I was frustrated with them...I think they are a very well made horn but there is something about the tone that has a bit of a huskiness, smokey...raspy color that I sometimes want to get away from...looking for more clarity..ala Getz on palm key notes on a ballad.
I also feel black lacquer is thicker too that is used on the Keilwerth, Selmer, Yamaha, Yanagisawa making for less vibration yet maybe a bit richer...I wouldn't say darker but warmer tone..a more velvety quality. Whereas to get that little bit of sizzle, buzz, complex harmonics/tone texture many seek...to get that "thang" that Sanborn, Berg is more easily accomplished with an unlacquered MKVI...or of course these days tons of players have gone to the Unlacquered Yamaha82Z...Jeff Coffin, Phil Woods, Bob Franchino (sorry for mis-spell...cat with Mike Stern), Dino Givoni, etc.
Plating is an entirely different animal since it is done on both the inside and outside of the horn...it is bonding another layer of metal on top of metal and yes I hear a difference in the horns....silver plating makes for a bit more brightness, brilliance in tone....gold plating makes it richer,darker and nickel plating makes it darker...just a taste less vibration...more focused "harder" toned to my ears.
Much of what I'm stating is how I feel playing behind the horn...what's coming out of the bell may not make as much of a difference...But it matters to me since I'm the one trying to produce the sound.
I'm partial to gold lacquered horns most happy with my Yamaha 82Z lacquered...and I've owned nearly every finish at some point...except gold plating...maybe that's next! Again this is my take on the cake and a personal preference....I know there is a lot more to the equation (like mouthpiece, reed, player) but I noticed a huge difference when flipping through Youtube last night hearing Pete Christlieb on a silverplate SBA, Gerald Albright on Black Nickel plated Cannonball, Bergonzi on an old gold lacquer Conn, Pete Christlieb on a Cannonball..maybe goldplate/lacquer...much preferred him on the SBA, Don Menza on a nickelsilver Keilwerth, Stan Getz on a MKVI.
Yes I know very different players with very different concepts but I do think the instrument/finish made a significant impact on their sound as well.