I think that's probably right, although I'm more nervous about the idea they should come across as radical. The sense I get is that radicalism is the opposite of what the median UK voter wants - if anything, it's a small 'c' conservative country. Being painted as a radical was one of the factors that counted against Corbyn, as far as I can see.
Although brexit could be seen as a radical change, I'm not convinced that it means the country has an appetite for more radicalism. I'd say the opposite - that act has satisfied a lot of the desire for a big change, and people want things which are or can be presented as common sense.
Maybe a lot of this is presentation - the Biden approach is interesting, as he came across as moderate, but that has allowed more wide ranging changes than I think he'd have got away with if he had campaigned as a radical 'change' candidate.