I guess as with most of the topic - different from one to the next. Vegans turn vegan for different reasons - connected to ethics. My main driver is climate change, biodiversity loss, with animal abuse important but a bit further down the list. (i.e. I don't think hunter gatherers were wrong - but they had a clear set of not taking too much and honouring what they killed ... so I am not entirely against, but very much so against the scale and the industrial nature of it; against lab research and against harm to animals). I would eat road kill, if I were living somewhere that'd be feasible - which means I am on a vegan diet, as the same person with stricter rules, but don't follow an absolute vegan philosophy.

[I'd choose wool over an oil-based or cotton wool t-shirt as the latter too are more damaging in relation to my core issues.]

So in this case - I'd want to look at energy costs, what it does to the big picture - i.e. what are the social outcomes. But I also eat vegan as a highly meat based diet just really isn't what we are designed for. And there's an aspect of power behind it, too - who is producing the lab meat and where do the profits go; what do they do with the profits?

I am partly vegan because "conventional" farming also contributes to biodiversity loss - and at least being more vegetable focused reduces, but doesn't eliminate that part. So ... loads a factors to see, observe, think through before I can have a clear ethical stance on it.