From looking at definitions of the prime meridian, I would say that committing the β-β is correct because most sensible software is going to use the simple test that anything less than 0 is West and, if the GPS coordinates are written as a string of characters, that test is usually implemented by parsing looking for the β-β symbol.
However, ExifTool shows the GPS position of an iPhone image asβ¦
[Composite] GPS Position : 48 deg 38' 49.43" N, 3 deg 35' 1.19" W
So there is no ambiguity.
Not being able to immediately go to somewhere on the meridian, I canβt verify what the iPhone would give for 0Β°