Why not just internally represent longitude as being between 0 to 360 (mod 360)? This way you won't have a discontinuity in direction when going from one longitude to another.
In a lot of ways, this is actually worse. Lots of software can ignore problems posed by antemeridian-crossing geometries because in practice, not that many people encounter them (not many people live there). This would move any problems to the middle of the UK, plus a good chunk of west Africa.