There is some latency, but it's not terrible. I was able to have a successful FT8 QSO and, as you no doubt know, timing is critical in the digital modes.
The only problem involved with mounting your radio in the tree would be that unless you have a rig with built-in Wi-Fi, you’d need to have a server up there as well and it would need power and some sort of network connection. Power is not much of a issue — the Linux version will run on a Raspberry Pi, which could easily run off a battery that’s hooked up to a solar charger. Connection that server to a network is not quite so easy to solve, though.If I can mount the radio in the tree with the antenna and only have a B+/- going up the tree, I'm in.