Well, here is what I think is going on and why it relates to the Wi-Fi chip, even if you might get a crash when on LTE...
The flaw in the Wi-Fi routers that have USB ports in them is that the header file for a packet being received by a device (the iPad Pro) misleads the iPad as to the real size of the packet. This is how hackers are able to use this as an exploit as well as it being able to crash a kernel; a header will inform the wi-fi receiver that the packet addressed to the iPad is much smaller than it actually is. It can be a massive disparity in size, this leads to a buffer overflow due to a memory leak being caused due to the system needing to store the excess data received in memory, while also not being able to access the data received. So it will gradually fill up the remaining memory until the memory is literally full when the computer thinks it has more room. This is when something has to give, and therefore the system crashes because it tries to free or store memory registers that don't exist.
Now why I think it will occur even when using LTE; normally when going from Wi-Fi to LTE storage, you don't even think about it, you either turn off the Wi-Fi or just go out of range. So you are starting with a kernel that already has a bad idea of what the memory state is. Now I don't know if you have ever programmed an iPhone or iPad application or not, but even when you try to code your program to be free of memory leaks, you will still program them in and you will only find out when you get crash reports back from it being in the wild.
You are thinking about it in relation to older computers correctly, because due to the high price of the memory being on the processor itself in phones and tablets, it must be limited. So 2 GB of RAM can be much more quickly filled with junk from buffer overflows. Desktop and notebook computers take much longer to do so these days due to the sheer size of the total memory (16-32 GB with the ability to use a hard drive to use as virtual memory). This is where the slow down comes into play with regular computers. Normally when you get a computer that hangs, you will reboot it and in the process will clean the memory out.
So I would still look into the wi-fi router you are using and see if it has the NetUSB flaw as it could still be leading to the crashes even when on LTE.