n2, why not implement build.prop changes in /system that only allow android to use 2G? I have done quite a bit of research on telephony connectivity in the Infuse 4G forums and I would assume it's the same across all Android platforms.
I would suggest...
ro.ril.hsxpa=1 (1=UMTS/GPRS [2G], 2=HSXPA [3G]) Just remember that the EDGE network is a form of GPRS, therefore it has a specific value for setting 3G services.
ro.ril.gprsclass=6 (or less as 7 and above is specifically 3G). See this
for more info.
There are other ril implements to use, but this is a start.
Also, there are APN configurations that restrict data speeds as well.
Is this for a HaReT install, or NAND?
Development device (still running strong)
AT&T Tilt/HTC Kaiser 160
Fresh Froyo 8/29/11
Scoot's 18.104.22.168 N50Vc Kernel
Samsung SGH-i997 Infuse 4G, Some form of CM10.1