Only a matter of time before DJI programs it out in a new FW. They simply have to make the flight controller regard the take off altitude always as zero on the moment of throttle up/take off. That way you never get to fly higher than 500m over the takeoff altitude.
And knowing DJI, they will lure everyone to update with a new thingy like 'asteroid' and don't tell anyone they fixed this as well.
I think they are HW restricted as there is no barometer in the controller. But, you are right, they will "fix" stuff in FW updates. Their simple "fix" for those using the vacuum chamber is to set altitude after launch...
I have a mountain nearby that I want to fly over but can't quite make it with the 500m restriction. I thought of using the roll back method but I would loose the Pano functions which I want to use on top of the mountain. True I could roll back to 03.700 and do pano stitching using another offline method (Photoshop).
Right now the vacuum chamber is the only way to get my cake and eat it to, maybe. I have seen some FW mods where there is a stitching of old and new FW to keep the 04.100 features but there has not been many reviews on this approach.
Maybe someday DJI will have a FW load that would allow you to accommodate flying to and up mountains. This could be done in the GO 4 app by using Google map terrain data to keep the MP some set distance above the current location.
DGI, I would also like the following FM mode and HW attachment:
A herbicide delivery system.
This would entail a small liquid storage container, spray pump, spray nozzle, and a connection to the MP for power and control. Also an auto-dock system that would allow the MP to fly home and recharge just like the several robot vacuums out there. Dock would have the remote control and internet connection to know when not to spray because of weather or whatnot. It can be done...