Depending on the plate design, the UPM can provide a far more immediate edge engagement. A lot of people feel that the delay in edge engagement, when riding a plate, is due to the height off the board. In our development of the F and AF plates, we found that the use of the UPM and different types of hardware generated a plate that engages the edge far faster than with the 4X4 pattern.
When plates first started coming out the flex patterns had not been optimized for them. shifting the pattern to the rear made it possible to load the board in a stiffer section of the board. As flexes have evolved to work better with plates, this has become unnecessary .