4096 is nothing these days ;) If you create the originals in 4096, you can shrink to match your pc capability and won't lose the detail which is why we do that in Excalibur. Creating them in 1024 and uping the size will just blur them.
That is good , to do [cause you want the detail, but many of us still don't have that big of a computer system] But if working with 4096s is to Large for your system Do Not do it.
I found on my compouter system , if I HP a Ship with 2048 sized textures, my MPE will not save correctly, now if I HP on a ship useing 1024s textures, the HP I save, can runn well not only on512s but 1024s and 2048s, I have not run 4096s [they wouldoverrun my system]