I suppose I don't actually see such a big difference composing with the 6x17 and the 75mm lens compared to say a 2¼ square Rollei with a similar focal length lens, the perspective is the same, so is the balance between foreground & background, only the horizontal angle of view changes very significantly. (Assuming landscape format).
There's a good reason for this, for many years I've often been frustrated by the 5x4 format for very wide views, far too much irrelevant foreground and sky. I have shot and deliberately cropped on a small number of occasions but I get no satisfaction working that way because I always compose tightly to the format. So when I bought a 6x17 camera it was from an informed knowledge of the type of images I would use it for.
Having had a look at your Portfolio, and a little of your website, I can see where you are coming from a bit better, and we approach the landscape in different ways. I use wide angles for 5x4 work quite frequently, particularly a 90mm, and when needed a 65mm, in fact in 20+ years I only shot with longer than a 150mm twice - a 300mm but I never used the images, although more recently I've begun using a 210 bought of one of the Mods.
So back to composing Panoramic images I guess I initially position myself for the vertical, then adjust my position to accommodates the horizontal, if that makes sense. Working with only one lens that means I should walk in or out, but I seem to be able to walk to the right spot subconsciously.