Yeah, I've improved it a bit with UI in the bootloader (still fits in 32KiB sram, even with GUI) + flickerless/seamless display pipeline passover to the kernel in the meantime too. :)
I've also experimented with booting to electron and having the whole phone UI written in it...
Batter gains in standby are something else. Main CPU is off, and no processes are thus running, so it doesn't matter what SW you have, for those gains.
I'm not so sure about booting into custom init in <= 1sec since nobody really looked into optimizing the boot process that much yet, but Arch in 5 secs should be easily achievable since booting Jumpdrive on Librem 5 with regular u-boot takes about 5-6 seconds already with no effort put into booting speed whatsoever. Just getting rid of initrd would already shave quite a lot of time.
Librem 5 has a slightly faster CPU, more than twice as fast RAM and pretty much the same eMMC speed as the PinePhone. Boot times should generally be similar, with Librem 5 slightly winning, and that matches my observations so far with similar distros running on both devices.
No videos yet though, I may record some in the future :)
Booting to my custom init process, initializing the system and running my UI app in ~1 second
Try that with any other smartphone...