I haven't used an XPT fpr a while, but was informed earlier this year that car A (the first class sleeper with 18 berths, converted to a 'day sitter' on day trains with 27 seats i.e. 3 per compartment) is no longer being made available on the latter. If true, retrograde!
This was allegedly because it was hard for staff to supervise passengers in car A, as it's at one end of the train.
Yet it's worked well for 40 years to have daytime travellers occupying the seats. Was this change a result of the union complaining?
Staff will not be occupying '27 seats' as the maximum number of on-train staff (excluding the driver) is five.
Be persistent and you may score. Not as if you're going to damage the seats.