Assuming a few things (some which are stretching things a bit):
1. You own the xbox and hence the right to all versions of the msdash. (Is this a valid argument??)
2. You have a game and you upgrade to 5960 dash with it.
3. You grab a copy of UEEE.zip. To generate 4920 dash files from 5960. Point 1 supports your claim.
4. You get a copy of Nkpatcher and compile it yourself. XDK-free.
5. You don't care about XBL access or Live safety.
6. You get a copy of the shortcut XBE which uses OpenXDK. Or a shortcut XBE based on nasm.
7. You piece together a softmod package with these contents:
a. 4920 dash.
b. Ndure fonts.
c. Nkpatcher. Configured to boot the shortcut XBE.
d. Shortcut XBE configured to run another XBE at a known location.
You distribute the softmod package. All your users own a xbox and the right to all these files. By itself, the softmod package is free of XDK-derived work. All it does is allow the user to run unsigned code like a boot disc.
The above points are purely academic and I've no intention of trying it out and I don't encourage anybody to do so.