I did injections and cannulas in bum cheeks for 30+ years. Legs bled too much and stomach never had good levels.
Had to come off pump as my skin everywhere started rejecting cannulas. Bum started not to work. Stomach no chance, constant failures. Tried more types of sets from different manufacturers than hot dinners (slight exageration) but all types steel, flex and all lengths.
I too was told by 2 hospitals that children can use them and they are skinny too..
I had absolutely no fat, just muscle and a bag of bones.
3rd hospital realised the probs were my skin, even in non used areas was rejectting after 5 years brilliant use.
No choice but to return to MDI. Diaport discussed but I really do not want to be a guinea pig, got enough probs with adding that to list as well.
I wore my pump(s) on arm. Nowhere else. Loved the cannulas in bum. Always steel ones.