"Trust me"
I don't.
I agree, don´t trust, test it youself . Build it, see if it works for
you at the TE probe, test other locations, improve it and give it back
to the gliding community. It´s $20 for material and some fun time
spent on a hobby, so there´s not a lot to loose.

which is why you see air-data nose booms on test aircraft.
Flight testing is a pretty different application with different
requirements than a simple DIY glider stall warning, isn´t it?

Nose cone sensors would be too close to the wing as well but the
location has proven adequate in a large number of aircraft
As you say, not a perfect location, but a reasonable compromise.

Come to think of it, I saw a photo of Mark Mocho's Pegasus with the
TE probe on the nose which makes a lot of sense aerodynamically - if
a line boy doesn't trip over it.
Aerodynamically better position with usability issues vs. fin mounted
probe as a reasonable compromise for most pilots, same situation as
for the AoA sensor position.

Michael