First seat mod I ever did to increase legroom before creating the MUD rails was to grind off the pressing in the seat frame that acts as the stop for the rearward travel. Slide the seat all the way forward and you'll see the pressing in the rails. Grind off the pressing and fill with a blob of weld. Once cleaned up the seat will now slide beyond the point where its used to come to a stop. Don't forget to add a spot of weld to the end of the seat frame to prevent the seat base from sliding all the way off!
Even with this mod you'll then run into the problem of the seat frame hitting the raised lip/seam behind the seat on the seatbox. Only solution here is to notch the seam or, I know it's not what you want to hear but raise the back of the seat. Hence the reason the MUD Rail was born!
After seven years of sales and literally thousands of sets of Rails sold, I can genuinely only ever recall a couple of instances of customers saying they thought the extra height made seeing out of the screen difficult. I' 6' 5" and have no problem with the raised seating position.