These motorcycle seats are just not made for passengers at all. I explain them as being a cheap divorce for your unwanted wife. (Just drop the clutch at 5 and she’s gone)
These motorbike seats are completely reshaped for rider and pillion. With most attention given to widening and shaping for passenger comfort, while the front is reshaped to relieve pressure on the tail bone and groin.
Many of these Triumph seats that I have reshaped have been fitted with the after market gel seats which do not address the issues specific to these motorcycle seats.