Thank you @nonsuch for this wide answer!
I don't know where to find Scout sources but I wrote to Nicolai. Maybe he'll answer if he is still around.
I also searched on his page here.
There is a link to the garage but I have no access there. IIRC, I tried to register but it was closed.
(For the recall, here are all the compiled packages/versions of Scout)

SDK+Gui is over my head. I could maybe, and would like, but I'd need 2 month study and training, I guess.

But why not doing something more user friendly in a script?
This is something I could try when I finish this full work period.
And when I'll feel there's nothing to try with GPS anymore, also.

A script and something like zenity. Would be easy!

But is SFos going to last? Although I am very pleased with mine, I read quiet a number of unsatisfied users reporting a lot of bugs in an atmosphere which is not...like here.
I am OT. But here, I dare, don't I?

EDIT: Forgot, yes SearchNemo, I had tried it. I was disappointed not to find something similar to Scout and maybe closed it a bit to early. Gonna try again.