New2cows, I'm in a similar boat. 5'7". First accept that a rider does NOT HAVE TO BE FLAT FOOTED to safely operate the motorcycle. Second, lowering a Concours 4" is an extremely bad idea, especially for the sole purpose of being flat footed. They only have ground clearance around 4.9". Lower it 4", you're scoot is 1" off the ground. That's insanity.
IMO as long as you can get more than tip toes down on both sides you should be OK. Check the preload, my 14's preload was cranked to the max (I was told they do this so that the suspension doesn't feel soft, and in case a couple wants to ride it) and didn't need to be. This got me a 1/2" lower. Consider a reasonable 1" lower link. Anything more than that on a tourer wouldn't make sense. Between those two things, you should be able to at least get the front 1/3 of both feet down. Another option is dropping the front forks 10-15mm (15 max) which is about 1/2". That's the last thing I'd do though.
I touch with the front 1/3rd of both feet on even pavement on my 14R. I do mostly urban riding. I stop/start frequently. I use safety techniques taught by MSF, and part of that is scanning the area you're going to stop for things to avoid (gravel, oil, dirt, pot holes, etc.). Probably not statistically, but as a non-flat footer I feel like I need to be even that more perceptive about where I'm putting my feet down. I do know first hand flat footers fall over sometimes too.
Like Rick84 says, you should check out different makes and models too. Concours has a strong following, but there are other bikes out there that are very similar and might cut you a little more slack. If you're deadset on a Connie, I'm sure you can make it workable.
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