Question about Toto Carlyle

live in Norway, but I like the American style toilets with the large water spots, since the European style needs use of brush after almost every visit, so I consider importing one, but, in Norway the rough-in is typically 3 to 4 inches, so my question is:

Will it affect the functioning if I use a straight tube right down instead of the unifit adapter?

It would not affect the flush, just not sure how you would adapt to the floor flange.

If you are sure the flush will work as normal, I will find a solution to adapt to the flange, there are lots of adapters for that purpose over here..