I’m not EagleEye but I know without any reservation what John created with his GPS tower provides improvements that extend beyond the GPS.
The tower alone increases separation between the GPS transceiver and the main power board, ESC’s, and battery. By itself it permits accumulated heat inside the shell to better disperse, which benefits not only the GPS and compass, but the rest of the electrical components as well. By reducing heat accumulation by by providing space for expanded air migration the life span of everything is extended. Heat causes a lot of damage to electrical components and the effects are accumulative.
Nobody that builds high end drones encloses the GPS module in close proximity to the main power system. The main power system creates electrical noise, which is known to interfere with GPS signal. So they place the GPS modules on masts that elevate the GPS module away from the power system. Consumer drones are tightly packaged with a captured GPS unit because they are cheaper to manufacture, and because the average buyer sees them as being cleaner in appearance. It also eliminates the probability end users might break the mast.
Last I heard, Johnno took his heat dispersal method to a new level by incorporating a cooling fan to improve cooling air flow inside the drone body. If that feature is still present it’s an exceptional benefit as the H body design has a deplorable cooling air flow design. The cooling vents do not face into the general direction of flight and the exit area provided is inadequate to properly exhaust expanded hot air. His fan concept largely overcomes a major manufacturer design deficiency.
When I was doing the battery testing I dug pretty deep into the H hardware just to see how they did things inside. One of the things that concerned me greatly was seeing the adhesive used to stick the ground plane layer on the upper shell burned onto some of the GPS and compass components. I haven’t gotten around to placing a thermocouple inside the GPS hump to establish actual operating temperatures on a normal day but seeing the adhesive burned onto those components and nowhere else was enough to determine there’s too much heat at the GPS and compass modules. If and when both fail you get a fly away, and neither the GPS or compass is certified to survive an elevated temperature thermal soak. I would be really surprised if either was designed to function above 40C. Mil standards use 60C as the minimum max level, and often higher for critical systems. That 20C delta is the difference between something that can fly on a hot day and something that can’t. I saw quite a few aircraft, manned and unmanned, that had to taxi back and park because their avionics cooked off waiting on a hot taxiway.
So do I believe Johnno’s tower result helps? Without any sliver of doubt, yes. The $7.00 eBay contraption will help a little but nowhere close to what Johnno’s will.
Just an FYI, a large part of my professional life was dedicated to finding and resolving problems. Although the title was field service rep it was more about being a “fixer”. Heat stress resolution, at either end of the temperature scale, was a big part of that.