What are the gotcha's we should know about before developing this app? It is going to be an embedded display for the LabVIEW exe. I've used LV web services and front panels enough to know that I don't want to go down that path.
Where should the root directory of the web page be located so the NI web server will find it?
Do I need to enable the server in the project for it to be active?
Presently I'm using LV 2018, but will move to 2020 when SSL support is released.
If you just want a web app to form a local display then I don't think you will see any major gotchas but I don't understand your architecture fully.
FYI - I was looking through the LabVIEW 2020 help and it looks like in 2020 you have the option to use the NI Web Server (as opposed to the application server) - if so this is apache based I believe and may offer more options. Again I don't know if there might be limitations as you are on an ARM rather than x86 RIO.