I'm not conflating them, I'm distinguishing between them. It's because they're already conflated that we're having this problem. I'm explicitly saying that the substrate is not what it's important here.

But this works both ways: what is the non-question begging argument that observer slices can only be regarded as older versions of previous slices in the case that the latter and the former are both running on meat-based substrates? As far as I can see, you have to just presuppose that view to say that an upload's observer slice doesn't count as a legitimate continuation.

I don't want to get drawn into a game of burden of proof tennis because I don''t think that we disagree on any relevant physical facts. It's more that my definition of identity just is something like an internally-forward-flowing, indistinguishable-from-the-inside sequence of observer slices and the definition that other people are pushing just...isn't.

All I can say, really, is that I think that Error and Mark et al are demanding an overly strong moment-to-moment connection between observer slices for their conception of identity. My view is easier to reconcile with things like quantum physics, ageing, revived comatose patients etc. and that is the sort of thing I appeal to by way of support.