I've built fiber networks and fixed wireless networks. Almost ended up becoming an LTE network as well. It didn't make any sense in any sort of financial modeling, even with spectrum availability.
LTE helps solve "general connectivity". What it does not do is build scalable, reliable, high speed, economical sensitive broadband infrastructure.
LTE is what somebody would do without much telecom experience and more money than sense.
I don’t know how much I trust TP Link, but my risk level is very low. There’s not much an attacker could do if they get on my network. None of my data is accessible on that network and everything important has MFA anyway. The most sensitive things are my POS and menu displays and they are just client devices connecting to the internet. I probably wouldn’t run this stuff in an environment where I had complex security requirements.
Cross platforms, really? So for example between a Blackberry and a Windows CE phone?