This is based partly on this thread:
https://www.b4x.com/android/forum/threads/sending-data-to-the-remote-compiler-error-b4i.124470/
To help with the "why does the compiling take so long", a report in the compile window with something like this might help:
At least would it help to short-circuit the threads asking why it takes long. With a report like that, it's fairly obvious it's the outgoing bandwidth from the client that is the bottleneck.
https://www.b4x.com/android/forum/threads/sending-data-to-the-remote-compiler-error-b4i.124470/
To help with the "why does the compiling take so long", a report in the compile window with something like this might help:
B4X:
Sending to Server1: 3 min 34 sec
Preprocessing: 2 sec
Compiling: 7 sec
Sending result to client: 12 sec
Total time used: 3 min 55 sec
At least would it help to short-circuit the threads asking why it takes long. With a report like that, it's fairly obvious it's the outgoing bandwidth from the client that is the bottleneck.