Hi @Steve.Enomoto, yes high altitude should be a challenge. I heard an advice on electric RC planes to inch up the prop there. (plane with 9 inch prop at sea level will require 10 inch.)
Not sure it is a good idea to give up Sky Viper’s Sonix wifi/camera board. SV flight controller contains Rx, so SV may be able to arm and fly without Sonix board, but I do not want to that because it is scarey not be able to connect APP or Mission Planner/QGC to find flight board status, not be able to log the flight on SD card…
Check this thread on brad112358 's effort to lighten SV by removing a few case and parts. He has posted detailed weight saving info somewhere but I cannot find…
I tried to transfer SV on lighter frame, described here. It is a bit of work and require another tuning.
There is a picture of inside Sonix board shield here. It provides WIFI connection, web server, camera and logging.