I guess I'll post the answer to my own thread question............
Even using a hybrid radio (that helps in N4), Carbon compatible kernals and radio hacks/tweaks and mods will not allow true LTE. Just for anyone who was having the same or similar issues with Carbon or otherwise, changing your APN in order to not force it to try ONLY to ping LTE will not fix this issue either. However, it is best to change the APN if your a T-Mobile N5 user anyway. (IPv6 to 5 or the leaser option, depending service location)
Sent from my Nexus 5 using xda app-developers app