I've been putting mine on my butt cheek since the start 8 years ago but mine are a bit smaller Estradot 50. Nevertheless I only get problems if like Ju Ju says they are along a seam line or waist band so I put them on the central buttock bit. Also periodically I have a feel (eg when in the loo) and press them down with a warm hand just in case they begin to come unstuck. I also find they tend to come loose a bit after rinsing off conditioner in the shower or an overly long soak in the bath (although don't seem to have one of the latter, these days!).
I hadn't though of putting them round the front - only because I would be able to see the marks and I only see these on my bottom when I change the patch

. Interesting idea though Briony, re absorption!
Hurdity x