I have heard about tools allowing to chunk big files and reconstitute them later, but I don't think it's worth the time you will dedicate to it for the use we have of the distro.
There are many reason for remastering, most people will remaster their installation as a sort of customized backup, for those, it should be easy for each person to decide what to do with their data files (copy to external media, copy to another partition and unmount it ...etc)
Other people may have other reasons, like creating live specialized distros for domains like education, medicine, engineering ..etc or backing up an enterprise central system, such installations are inherently large and it would be very usefull for such people (and others) to break the 4BG barier
My own reasons are even different
First, I don't like to be told that "it can't be done". In computing, almost every thing can be done, you will never know until you try, and even if the tools are not here today, someone will make the tools tomorrow (probably the person who was told it can't be done, and decided to do it
Second, I like to keep my brain engaged, I am 67 years old (a dinosaur) If I don't use it, it will die from disuse atrophy
Wouldn't that look KISS ?
Some of us don't know how to KISS