I don’t think that’s a problem particular to your car – when we were “test-fitting” the XC40 a year ago, that was the biggest reason for not even test driving it. My wife (with hip issues) immediately said that the seats were uncomfortable, took her less than 5 minutes of sitting in there, “there” being an Inscription Pro.
There really is only two options from what i’m gathering – either cancelling early (which would suck since you seem to get on well with it), or trying a decent seat cover (not a cheap one).
In terms of replacement, not much choice – Kuga PHEV has a CVT which is just awful, Grandland PHEV is a Vauxhall and they want £7000 AP, the 3008 PHEV which we didn’t like the seats of (too soft, not enough support at the bum/hip), or the Tucson.
All of which are high in AP, not sure how much the Volvo was – but the 3008 being the cheapest at £4400 (top spec not available on the scheme), ..
Prior: SEAT Ateca Xcellence Lux 1.5 TSI DSG MY19, VW Golf GTE PHEV DSG MY23
Current: Hyundai Ioniq 6 Ultimate
Next: we'll see what's available in 2028.