Thanks for all the replies. I’m going to try the following:

install a set of Hardrace toe and camber arms. I was able to buy them for £320 (about $370) so thought they were worth the likely reduced tire wear



reduce the rear toe setting to the factory minimum or even a bit less and reduce the rear camber to -2 degrees

stick with factory pressures

check the tire wear every 1000 miles and tweak the above as needed.