Is this Drotec you mentioned?I agree with your assessment of the location of the stock Solo GPS receiver. FWIW, I went the route of installing two mRo GNSS receivers in impconcepts masts. And an earlier Drotek GNSS receiver in an impconcepts mast. A bit of DIY drilling and cable extension work, but all three work very well, given the local trees, buildings, hills and other location attributes. For reference in the field (or just outside) I check the GPS Plan app on my iPhone to see which satellites are possible for the GNSS receiver to lock to at my current location (and assuming a flat, uncluttered landscape which it almost never is on my jobs), and as allowed by the elevation mask setting. The most sats I have seen locked to-date is 28, but that is rare. On the app, the two views I use are the bird's eye view of the globe, then I swipe to see the optimal time of day to launch. Nifty to see the change from hour to hour in forecasted DOP values based on which satellites are visible. I tried one of the cheap GNSS products, but I'd rather not take the risk on a paying job.
Ublox NEO-M8 GPS breakout board
Can it be placed instead stock Gps without other moding except wire splicing?
I'm in Europe so this is fastest and one of the cheapest option for me