It turns out epc.t-mobile.com IS the LTE APN. And we are supposed to use wdm1, wwan1 with this modem. I am able to connect using those and do a speed test. Seeing about 3.5Mbps to 19+Mbps speeds. Average around 7-8Mbps speeds. I assume that IS the LTE, not HSPA+
root@OpenWrt:/usr/share/udhcpc# qmi-network /dev/cdc-wdm1 start
Loading profile…
APN: epc.tmobile.com
Starting network with ‘qmicli -d /dev/cdc-wdm1 --wds-start-network=epc.tmobile.com --client-no-release-cid’…
Saving state… (CID: 12)
Saving state… (PDH: 1137821672)
Network started successfully
root@OpenWrt:/usr/share/udhcpc# udhcpc -i wwan1
udhcpc (v1.22.1) started
Sending discover…
Sending select for 162.164.85.106…
Lease of 162.164.85.106 obtained, lease time 7200
udhcpc: ifconfig wwan1 162.164.85.106 netmask 255.255.255.252 broadcast +
udhcpc: setting default routers: 162.164.85.105