my settings that I found to use are this and I have this with 1 subtraction as I don't have the option.
NAME st lte
MMS PROXY mms3.tracfone.com
MMS PORT 80
MMS_APN tfdata -- don't have MMS_APN
My wife has the same phone and the sim card was purchased at the same time, she is getting 14MBs down and I believe her MMS is working.
We are both on the Viper rom, i have hboot 1.44 she has 1.55 that is about the only difference.