I need a little more leg room and have thought about lowered footpeg brackets like I've put on a lot of past bikes but although the gear linkage looks easy to adjust, the rear brake not so much so and as it is, I have to lift my foot off the peg to use the rear brake so another inch lower would make it worse, hence the thought of a taller seat.
I have both the OEM seat and Suzuki Gel seat for the newer DL650, and the Gel is clearly taller, maybe 1/2", perhaps a bit more. Not sure if the difference is sufficient for you, but the Gel is more comfortable as well.
For more money, the Adcox would be a better solution, as its taller and significantly more comfortable than either OEM or Gel, based on what I have read here.
I can confirm that moving pegs down 1" (25.4mm) and
using the Tall OEM seat, adding about the same in height..,
is much easier on my old knees at least...can slide back more in
the seat which is great for longer arms.
I will use the Tall OEM seat for my '14 DL 1000A and
maybe just keep the standard OEM to experiment with
using air cushion or sheepskin....anyway I like the extra
2" or so ... easier on the knee position for long rides.
Just my observation but confirms your previous mods for better ergos.
Good luck finding a taller seat.