I'm 5'7" with a 29" inseam and enjoy riding my ST1300, but need to plan ahead whenever stopping.
These have been tried on my bike to keep the height manageable:
Spencer seat: I sent my stock seat in for modification. Lowered the seat height, but it wasn't comfortable for my backside. I still have it as my backup seat.
Corbin Close Canyon seat: I bought this one used. Comfortable for my backside, comfortable for my back and wrists, lower to the ground, but my wife hated it. The geometry between the Honda top box backrest and the passenger seat pocket don't match up. Sold this one to someone in this group.
Russell Day Long Sport Seat: This is my current configuration. I sent a set of seat pans to Russell to build a Sport Seat, not a Day Long, for my ST1300. The Sport seat can be built lower at the sacrifice of some comfort. The height is not as low as the Corbin or the Spencer, but still manageable. It's comfortable, but I can't rave over it as some do with their Day Long. My backside is no longer the limiting factor in how long I can ride. Passengers are comfortable.
Wilburs shock with shortened travel: Currently installed. No problems with the side stand. Center stand use is tough. Get help or put a plywood shim on the floor first or risk hurting yourself lurching it onto the center stand. I can drag nearly everything on the ground if I'm cranked over HARD in a corner, especially with a passenger. All the plastic under my bike is scratched up, plus the center stand and the pegs. I keep the stock preload cranked up most of the time. With the roads I prefer, my tires tend to wear out on the edges before the middle. Not sure I'd spend the money again on the shock, but a used one popped up here and I gave it a try. Somebody who only commutes or sticks to the slab might not notice the ground clearance issues.
The shortened Wilburs shock with a Russell sport seat is where I've settled for now. Crank up the preload, especially with a passenger, and it's working for me. If you can't stand to touch down once in awhile, don't use a shortened shock.
Lift boots might be the cheapest option to try. That might be next for me.
HTH, Ken