Excellent - Some feed back.
YES! it's all being done already - so it's a tried and tested solution

. Largely what I'm recommending is the
purpose the various exploits are put to.
The original Easter egg exploit was used to go from a
safe state to an exploited one.
With the Ultimate Dashboard Exploit you can boot directly into the exploited state.
I think it's fair to say that the exploited state would be used more, so the Easter egg's finger dancing makes it inconvenient for frequent use.
At this point, it's worth reminding the readers you can still
play XBOX!Live games, from original media, in the exploited state - you just can't use the game's link to the XBOX!Live console.
Once in the exploited state, you
could use an Evox script to perform the
renaming (as you point out), but because some people prefer alternative custom Dashboards that may not contain scripting, this is not an option for all. However all custom Dashboards allow the execution of an XBE, so putting the all the necessary
renaming into an XBE would suit everybody. (Making the bert_ate_ernie font execute this 'C:\RenameSafe.xbe' on a held-button press skips even the need to enter the custom Dashboard).
What's new in what I propose is to use the Easter Egg exploit (which currently works on all Dashboards) to re-enable the Ultimate Dashboard Exploit, from the
safe state. No need to scramble around finding your exploited game DVD, etc. It's all on the HDD.
All the bits actually exist on the scene for anyone to configure their XBOX this way, but I feel that it would be made simpler by a new DD bert & ernie font, for use by the Easter egg, that'd execute a 'C:\RenameUDE.xbe', and, ideally, a new bert_ate_ernie font, that'd launch 'C:\RenameSafe.xbe' on a held-button.