The problem is not saving to disk. That's never been the issue. The real problem is that it was designed for a specific use and the our system ain't it.
EG was made for the purpose of loading into a flash area on a supported motherboard. In that case, you have a super fast booting mini-OS when you have nothing else installed. Heck, you don't even need a hard drive then.
Sadly, ASUS and EG decided to come up with an "expanded" version that could run off of a hidden partition. This means that the they locked is down (no HDD at all) is gone, but they didn't bother to open it up to use the HDD space its installed on.
So, we end up with a "Firefox" derivative that can save bookmarks, but can't install extensions. We have an install designed to fit in a tiny flash, but can actually use gigs of space.
Its a lazy solution and makes it pretty worthless.
I am thinking about messing around and trying to hack a small true linux install in there and see what happens. The new alpha of Ubuntu has a boot time pretty close to EG anyway.
If you want to see the difference between a hack job, like EG and a real fast boot OS designed for a system with a HDD, check out HyperSpace. Sadly, it won't work on an N10, but its sweet.