Burnham losing today would be the most entertaining timeline. It would throw Labour into chaos.
Reform contacts say they feel it's 60/40 Burnham wins - they think they could do it, and they've got a big enthusiasm gap, but beating Burnham is a very big ask.
I don't know about Restore. They've got a very effective Facebook operation that seems to be cutting through with women (though it's a bit cheeky saying "Vote Restore because the Reform candidate said some sexist stuff on the Wigan Warriors forum 10 years ago" when your party's propaganda chief is Carl Benjamin of "I wouldn't even rape Jess Phillips" fame)
They've also got attention for hiding their candidate and not letting her do interviews; the Mail have done a few exposes on neo-nazis in their ranks; and you hear about just general oafishness from the activists they've sent to canvass in Makerfield. Once you look past Sleepy Rupert, it looks less like a party and more like a Nigerian email scam.