Seems everyone is making this too hard.
Here's the bottom line on getting Boost to work. I have Sprint TP2s with Energy ROMs on Boost with no issues, including working MMS.
1. use my energy_sprint_mms.cab file instead of the stock Sprint provisioning:
http://forum.ppcgeeks.com/2041299-post29976.html
All this does over the regular one built in to the current ROMs is the Arcsoft UI MMS limits is updated to 5mb
2. load my attached custom registry file. It does 3 things:
a. sets the receive MMS server to specific known working one
b. sets the send MMS server to boost's.
c. sets the Append URI registry setting. THIS IS THE ONE that has prevented folks from having MMS work properly. I know, I went through EACH registry item from the other threads to determine which one was specific to making it work. The folks on howard forums also validated this is the primary registry item that broke things for boost users.
These 2 items are ALL that is needed for Boost to work with the CDMA Energy ROMs.
Teradog, I'll PM about putting in a simple wiki entry on getting Boost to work on CDMA Energy ROMs. The other Boost threads on PPC are too generic and meant mostly for stock sprint rom TP2s.