The interesting thing about the timeout genes, is that they are there for a "reason". It's a species' built-in population control mechanism to ensure that resources are spared for the younger generations. Evolution has put these genes in almost every living thing, to ensure that they eventually die.

So there is a "meaning" to death, when understood from nature.

Can you be more specific? I've heard the argument, for example, that cell death is a defense against tumor growth, but we do not observe that across all living things - we have Peto's paradox where large animals have almost no incidence of cancer.

I'd be really hesitant to try to attribute any one specific reason as to why we age, or why that has benefited some life.

Yep, retrofitting can be hard. But if you figure it out for babies, Im not sure why you couldnt ultimately use the same ideas to also start changing genome of existing bodies. Obviously, there are more cells to change. But at least you dont have to wait as long to see the effect.

There’s also no fundamental reason that all this bioengineering will not result in a new ‘species’ with say an average IQ of 200 and a consciousness five times as large as humans’. How long would they want to live?