ok so 4g has been tested and working on sprint based roms using this patch? because if so i may have a solution for aosp based roms
youll need to remove specification of the virgin network in the buildprop first off, aosp doesnt like that, might be able to leave it out and just have it tower selected but i would say a safer bet is setting it to sprint 310120
also, i noticed youre using a larger apn than me and you have pamsn and n.ispsn which are sprint where as boost uses boost.pamsn and n.boost.ispsn so you might wanna check a backup of a stock apn pulled with an apn backup utility to verify accuracy. make sure to pull it from stock rom tho. and you will also want to check the duplicate lines and such but this should be the apn necessary for lte...
http://unleashedprepaids.com/upload/devs/junkie2100/apns-conf.xml
to install put it in /system/etc/ overwriting the old one then factory reset in cwm or twrp or clear the apn database using a 3rd party app. or you can manually replace the apns-conf.xml in the zip provided in the op using just about any archive manager and just install it as normal