I solved my butt issues on the Silvio V1.0 with a 45 degs Al seat that is part of the frame, by
reducing the shocks reaching my delicate THIN rear end!
First, I increased the tyre size to the max the forks would take with a bit of filing, 700*28 Ultremo ZX,
and the correct tyre for a 15% vertical tyre deflection, to give the
first isolation of shocks, and minimum rolling resistance, especially on chip seal roads. On the S40 that would be 700*38 tyres
http://www.adventurecycling.org/default/assets/resources/200903_PSIRX_Heine.pdf
Secondly, I fixed the front air cylinder suspension in the steerer tube that was leaking a lot, as it made heaps of difference on the poorly maintained bike tracks in Sth Aust!!
Thirdly, I replaced the rear stiff 1.6 mm Titanium leaf spring and PU spring, with an air bag and 0.47 mm SS spring, so the rear suspension FLOATED on AIR with 25 mm travel compared to 10 mm!!!
Fourthly, replacing the standard seat cushion internals with 3, then 4 layers of 10 mm thick Ventisit type foam inside the existing seat base and the seat back Cruzbike cover!
https://www.empind.com.au/shop/item/air-circulation-mesh-acs10
I had to adjust the boom length after the 4th layer!
The 4th layer made the difference over a section of bike path, near work where pine trees were planted 50 years ago on each side of the path for shade, but now creates 100's of speed humps!
From all the comments about Thor seats, I would go that way, with a thick ???? mm Ventist seat pad, + 700*38 tyres!
Don't go down the Vendetta Racing Bike rabbit hole, as you have a GREAT TOURING bike!!