With the exception of materials, the peak 5 is pretty close to the peak 4. The firefly v2 mod (viewtopic.php?f=197&t=2407199) showed that a small change in bridling by adding additional connections can have a big effect. For that mod, the additional connections are for row C. For the peak 5 they are on row B (see the lineplan picture below).
Given that single skin kites are very easy to sew and mod, it should be fairly easy to do a mod on the peak 4 to give it a bridle similar to the peak 5.
Anyone interested in this idea?
Summary of differences in bridling: without looking at the actual bridle lengths we can see the extra B attachment points and a C attachment that has moved towards the trailing edge. It also looks like a couple of A lines have been removed from the center.
My first question is whether one can get away with trying a mod just in the center section of the kite. This may have a strange effect on C, but it is hard to tell. I guess the next step is to study the line lengths to see how big the overall changes are.