Ok. Lets start again.
Festool parallel clamps.
Attach one guide to the rail. I have no doubts that that single guide isnt exactly at right angles to the rail, and if i were to press it to the side of a board, it would be as square as squareness gets. I dont see something coming from festool as being anything other than perfectly square.
Place the other and measure the distance top and bottom i believe they will be parallel to each other- because if they weren't, then they wouldn't call them 'parallel guides' would they
Everyone getting the concept ?
Right.
Without adding the bottom stops that give the depth or length(you know what i mean) i can place the track rail on a board of any width, slide the parallel guides so the contact the sides, and even push them in snug so there is no play, the rail will be exactly at right angles to the board.
This can be checked by sliding it fully forward so it lines up with the factory edge.
Sliding it back the required distance, make the cut, your cut piece should be perfectly square. I would be placing the track onto pencil marks to give me the depth of each cut piece.
Slide it back to the next mark, make a cut and so on till i have as many pieces at my width will allow on the length of the board. so if im looking for 700mm, ill get three pieces out an 8' length.
Everyone understand where im coming from here ?.
I really dont believe that festool would make an attachment that when fixed on isnt going to be square and parallel. Sure it might be out by 0.5 or less of a mill, but that type of accuracy is acceptable on a kitchen door or in fact just about anything we can make furniture wise.
These tables with the dog holes arrived long after track saws appeared, so shopfitters would have been using the parallel guide pretty much in the manner ive described, or just laying the rail on the board and cutting it to pencil lines, with clamps to ensure nothing moved during the cut.
So the MFT isnt a necessity, its handy, it allows accurate right angles, parallel cuts, but its not needed really. To have accurately sized sections, the parallel guides would do the job just as well. and in that task we've been making similar in mdf jigs for far longer.