Sorry a little late to this. but I have managed to lower mine over two inches without any issues.
As Taffy noted, the bushing is the way to go for sure, For the PDS this is the best way to a drop without doing the shock and without screwing with rake and trail. I also don't like to modify a shock for PDS types as the procedure used lowing will take travel out when bottoming.
I used the offset bushing,( I used the Synergy X-Bushing & Z-Bolt Kit as it also allows you to grease the bearing as well
) I had to shave the lower mount of my shock and did this with a die grinder and a 3m rol-loc disc, this took off just the right amount and did not compromise strength.
I also had to shave the swing arm to allow the shock to move freely with the offset bearing maxed out. The little amount of offset makes for a big improvement at seat height.
I also shaved the seat as this is not a cruising machine lol
Due to using a offset bearing in a PDS system, unlike the linkage system you do not screw with the rake and trail as much as all that is moving is you. I do not advise lowering the front in the triple trees the same amount as this will change the feel and factory handling. The offset bushing moves the bolt a small amount and due to the angle of the shock creates allot at the seat so the rake and trail change is minimal. Unless you really need this or are trying to achieve a faster turning response? If you do require this to get lower than take it a little at a time as per feel for you ( I have notice the 4cs seem to flop if you bring them up to far and will do this much faster as the flop is to the right and with the one shock being rebound and one compression this happens fast? and at high speeds), so be careful if moving them or have the front 4cs shocks done by someone who knows how to work on these correctly as they can be messed up and are quite a bit different than any other WP fork. My seat height is now 36 inches from the factory 38.19 inches.
I hope you enjoy you 350 as much as I do
Nothing but good things to say about this one