Reform won’t get as many seats as that, because far too early to factor tactical voting into the data. They’ll enjoy an huge increase from 7 but not 250-260.
Unless Labour have a Truss event they will get a lot more seats than that although it will still need a huge Job Centre+ for their unemployed ex-MPs in 2029. Green support well overstated, imagine that leader in an GE, Tories 100-150, Lib Dem’s low 100 maybe more if Labour don’t grow a backbone on Brexit.