Had a set of ICON 2.5 with remote res. installed on my 2019 4runner, non-KDSS. Yeah, probably should have looked things over but installers said no problems and off I went. Had no reason to doubt as they have a good reputation and I've been there before. After home, looking at install and saw they cut the fender plastic to get the RR mounted and now it's in contact with the washer resevoir. No, not moving but thinking over time it might rub a hole in it. I'll see what I can do to get clearance but wondering if others had run into this.

I did my King install and the reservoir bracket is contacting the inner plastic around the washer reservoir, it’s a tight fit for sure... not sure why they cut the plastic though... that would concern me too as now like you said the washer reservoir is exposed

They are both body mounted, so there should be no movement between them, and the bottle is thick ABS plastic, it'll be fine.
Scratch that, my assumption was wrong. Having something frame mounted touching something body mounted is no bueno.

Unfortunately the Icon and King reservoir brackets mount on the frame via the swaybar bolts. I've had both types on the truck over the years. The KING brackets have more clearance though.

To the OP I would be really careful about this. I actually had my washer bottle punctured by the Icon bracket when I was out romping in the deserts of Moab and bottomed out the front suspension hard. The body mounts flexed to put enough movement sending the sharper end of that bracket through my reservoir bottle. Later on I took the bracket off and shaved down the metal for more clearance which could be a fix for you as well.

I looked into it today and was able to work it out. There was a bit of weld edge sticking out just at the rear of the bracket. Removed, ground down that bit, little paint and was able to slide it back just enough to give it obvious clearance and still good clearance from the UCA so no worries there. I also put the pipe clamp through a center cut-out (which showed "4Runner use this one" on directions) that pulled it back a bit too.
Lastly loosened the bolt there at the bottom of the wash resevoir just in front of the mount and pushed it fwd. All adjustments made some space.
Maybe the tech got target fixated on the one spot and didn't look around at other potential issues... Kind of annoying they didn't mention it but it's just a cover and I won't see it from the drivers seat.