Your Garmin help, please

2 things.

1. I need a magnet that's super slimline to fit for cadence (800).
   
2. Why does my garmin, when deciding a route decide on the hillier of the two options? Does it hate me? I mean initially it's charming, and the first couple of hills you're excited, but later on you just wish it would follow the flat road.
   
   

That being said, some roads I took today were absolute road porn.

Rare earth magnet attached to pedal axle?

Garmin doesn't know the elevation profiles IIRC. It thinks everywhere is flat.