According to the thread on BROL, Christine at Performer will configure a highracer with small wheels, as shown in the top pic (yellow bike.) The major differences between that and their folding lowracer are that it will have a longer wheelbase than the folder, and of course it won't fold. Note that Performer also offers a folding highracer.
That said, the small wheels and associated fork will cause the rear dropouts to be about 3 inches lower than the highracer, and the headset about 6 inches lower. That will steepen the head tube (as Skankingbiker has acknowledged.) Even if the steering angle didn't change, the shorter fork will not extend as far forward as the longer one would have, meaning the wheelbase will be an inch or so shorter than it would have been with the full-size fork. Effectively, you'll have taken the folding lowracer and moved the rear wheel back several inches, which will help bias weight distribution toward the front and hopefully give better traction on climbs.
Personally, I think the package looks nice with the small wheels. The folding lowracer looks too short, IMHO. Small wheels are good for lowering the seat, or for a folder. If I were to do it, I'd be doing it for the latter reason and would start with the folding highracer; but that's me. I hope the modified highracer works well for you, SB. (And be sure to post pics.)