I found the last two build/repairs that shielding the GPS cables, and connecting the shielding to earth, adding a link to the ground in the GPS connect to the copper foil wrapping. Make a massive difference in terms of GPS sats and lock time.
I think I may continue this in future builds.
I am alone ?
Example:
@bmsleight
This has been discussed for ages now, it’s great that you have had measurable and definite success
I’ll give it a try on my smaller quads. Fortunately I don’t have issues on my ‘winged things’
I have a couple of new GPS units on the way from YourFPV. Maybe I’ll give this a go. Maybe (more likely) I’ll just do the bare minimum required to get them fitted and working. 
I aways do this and it makes a significant difference.