PARTUUID is totally independent of any initrd. For determining PARTUUID you only have to parse the partition table, which the kernel does anyway.
Incorrect, when you use an initrd with udev that does NOT create those links it does not work. Without it works, you can use Debian wheezy to verify. If your udev creates those links it does no matter.
For those interested, I've posted the results of my experiment in a thread at Kubuntu Forums. I've discovered a couple interesting quirks along the way. Fun stuff, though.
Well some things to add. Basically you would not need the .efi suffix when you use efibootmgr, you only need it when you use the efi shell. I hope that many Asus users will try adding a 2nd boot entry as latest uefi updates broke this. It is impossible to add more than 1 entry with the same -l option because only the latest one survives a reboot. Asus responded that Linux was not an offically supported system. If you happen to be an Asus user with that error just change the filename for the -l option a little bit - as it is fat you can swap upper/lowercase on any char - at least 1 char must be different. The extra options at the end or the label do not matter for this stupid uefi bug. Most likely it was done because Win is always detected and when you reinstall Win you would get double entries with this UEFI in the menu - others can do more, there you require a new efi shell or just linux ;) Btw. this is very important: if you want to delete boot options, then remove ONLY those which are not created by the UEFI setup itself. This can kill some systems, a bit critical for laptops as you have to flash the chip again. Desktop board can be fixed more easyly by swapping the chip - some new Asus boards (series 7) happen to have even a new usb recovery flash way that works even without cpu - good idea because the system would not even POST in a worst case anyway...
Btw. do you know
I've been playing around with this stuff for some time now. I certainly don't claim to know everything (yet), but it's been fun. If you're curious, here are a couple more posts where I chronicle my experiences.
* How I (sort of) conquered UEFI
* My UEFI fright: did I bork my X1?