That's a limiting factor in our current form factor. We so far have yet to identify a similar physics-bound reason preventing us from transferring consciousness

That's a limiting factor in our current form factor. We so far have yet to identify a similar physics-bound reason preventing us from transferring consciousness and identity to a different substrate, or even a computing substrate for that matter. Admittedly, we still are in the very early stages establishing exactly what consciousness and identity are, so it is premature to claim that we can perform the transfer in the future. The most we can assert at this moment is based upon the laws of physics as we know them today, we can hold out more hope for transference than breaking c. Similarly, we are not aware of any physics-based reason that prevent the design, construction and maintenance of computing substrates that renew themselves over billions of years. There are certainly political, cultural, social, even energy limitations, but nothing quite as hard as the c limit. So theoretically, we can hope to even in this reality to eventually create versions of our selves that reside in computing substrates and "wake up" for "interesting" events along a multi-million year journey. Perhaps they run in a low-power mode, where 1 day in real universe == 1 second in the substrate. In that context, even if we never go faster in that future than our current technology's Juno space probe, a trip to Alpha Centauri is "only" 17,785.27 years, or 12.35 years subjective substrate time, enough to get excited about and study the torrent of increasingly-fine-grained data pouring in from the real world about the destination. If the galaxy is relatively teeming with these compute substrate hibernation ships, then that presents interesting possible resolutions to the Fermi Paradox: what we are doing today on Earth is not "interesting" enough to the automation on these alien ships, or we are deemed interesting, but even the nearest ship within our light/EM cone is still thousands to tens of thousands of years away. It gets even more interesting if we figure out how to "decant" substrate consciousnesses into physical bodies. Even at that glacially-slow crawl of the Juno space probe, it would still take "only" 383,551,218 years to traverse the Milky Way's 100,000 light years. Put up against the ~13 billion years of the Milky Way's existence, that means spreading across the Milky Way is still within the realm of not-ruled-out-by-physics.