I didn't think it was confusing, my apologies.
to make it somewhat clearer, the whole point of my question is/was:
Is the increased comfort increase running 28s significant enough to justify getting a set of wheels build to run them.
To further explain the logic behind asking about a new set of wheels and the reason I think that in my application I would need them...I have not laced on up, nor do I own a set of rims that are designed for 28mm tires, I will assume that a rim designed for a 28 ever so slightly wider than a rim designed for a 25, so when the calipers are adjusted to the rim they will start ever so slightly wider, and this will result in them being opened ever so slightly wider when the cam is released and thus probably clear the inflated 28mm tire when the wheel is removed, as opposed to a caliper adjusted to a wheel designed for a 25 that would start adjusted with a narrower gap for the slightly narrower rim and would have a smaller opening when the cam was released that may not allow a 28mm tire to clear.
As noted elsewhere, my current setup barely clears 25s so I'm confident that I could not get a set of 28s on and off w/o playing with the barrel adjusters, and that's kind of annoying.
First, yes - the increased comfort is significant, 'specially if you're not a lightweight that can get away with running 25s at ~80psi.
Beyond that, yeah, you're needlessly confusing things - just throw the "designed for" stuff out of the window. What you seem to want is a higher volume in the tires and a mounted width that more closely matches the brake track width so as to make wheel install/removal easy - is that correct?
The first thing that you have to check is frame and caliper clearance (I'm not talking about the pad width opening at this point) - if 28s mounted on your current wheels are going to rub your frame/calipers, 28s mounted on even wider rims is a non-starter. In this case, 25s on wider rims
might give you the volume/lower pressure that you're after while still fitting within the confines of your frame/calipers.
If,
other than your how much your pads open when operating the cam, you have have room to accommodate 28s on your current wheels, then you'd have to consider how wide the 28s would be if mounted to even wider rims - they might be more like a 32 and that type of clearance isn't very common with rim brake frames (other than some vintage stuff or some of the very latest frames). If you do have the room to clear that ~32mm, then yeah, wider rims with 28s would probably do everything that you want - they'd give you the volume to run at lower, more comfortable pressure and be easy peasy to put the wheels on and to take them off.... but it's unlikely that you can accommodate that - it's one of the reasons that some people, myself included, decided to move to disc brakes.