I know a few people who have voted Reform, or who are likely to have voted Reform (I've lived around here, on and off, since I was born, so I know a lot of people, from the deeply posh to the descendants of farm labourers whose families have been around here for, literally, at least 400 years). From what I have seen of their FB, and what I know of them in general, they are:
Worried about immigration in terms of housing. They're rural people who resent fields being covered in concrete and the wrongness of digging up Grade A agricultural land to replace it with houses does their heads in; at the same time their kids can't get on the housing ladder, so more head-doing-in.
Worried about immigration in terms of social change. On the whole, they DGAF what colour you are, so long as you get with the programme. The whole ongoing grooming gangs scandal is something else that is doing their heads in.
Socially conservative in some ways, but not that bothered about parents being married or not, and generally not bothered about people being gay. But you should earn your own living, keep an eye on your old mum, and not nick other people's stuff.
They are, on the whole hard-working people who don't take the piss. And they're fed up. They're fed up with house prices, wage stagnation, the state of the NHS, the lack of policing (rural policing is a joke).
The big parties have gone off on insane tangents (Labour: TWAW, changing the rules around farming at the drop of a hat; Tories: managed to fuck everything up; LibDems: TWAW). So they feel that all these parties have got their priorities badly wrong and have abandoned the working class.
I can't see many (any) of them voting for Corbyn.