Are Labour in favour of changing the voting system?
I don't think they are. Why would they be? It doesn't make any sense for them.
https://www.theguardian.com/politics/2021/sep/27/unions-vote...
https://www.theguardian.com/commentisfree/2021/sep/27/propor...
And even if members were, the PLP certainly aren't - as they'd lose their jobs.
there was a consultation and its results were quietly buried
no reason to expect it would be different next time