So, there's actually a proposal for "real-time" communication between galaxies. Just upload your consciousness to a computer and run it slow enough that a few hundred million years feels like a couple seconds.

Slow time is a thing on a few Egan books were the population (of effectively immortal post humans) of some planets collectively decide to slow their internal clocks to allow some of their members to take interstellar trips without missing out too much of their original life.

The trips themselves of course consist on transmitting the mind to be downloaded on a new body on the other side.

I don’t really see the benefit. But running that slow, you might experience the heat death of the universe in your lifetime!

The idea is that you've already dismantled the stars and stockpiled all the energy in the universe, to use at your leisure. (i.e. everyone lives around black holes they can throw mass into to reap the bawking radiation). Since you have control over the last non-entropic systems, you can tune how fast the candle burns.

And you're a mind running on a computer! You were already going to experience the heat death! This is just a scheme to get the most subjective time out of it as possible. (Running slower is more efficient.)

Bay Area, 1960s: "Soon we will have computers the size of a single room"

Bay Area, 2020s: "Soon we will have rooms the size of a single computer"

"Vertical sleep pod, extra large (room for iPad on ceiling!), $3500/month"

this has been tried before. the vast majority of the smaller people that get made simply keep getting bigger until they become normal size.

We need to make them make even smaller people before they grow (up? :)!

That would have a nice side benefit or making space exploration much more economical. Faster too if you can bioengineer higher G resistance at the same time. Maybe someday the outer planets will be colonized by tiny humans measured in millimeters, with 125mm humans darting around the various moons shot out of repurposed tank canons, all laughing at the slow giants stuck down the gravity well on Earth.

Their tiny brains might be an issue for space exploration. But ideal for setting up a government when they arrive.

Or just normal sized humans simulated on a supercomputer the size of a matchbox…

Then how will tinder be? "If you're less than 10 cm don't talk to me midget".

OTOH can the heart perform equally good if human get miniaturized?

This is one reason an all female astronaut team has been considered.