I always request
2 keys, I keep them in separate pockets--both away from cellphones and other "magnetic" devices.
The + of check/in via cellphone is no waiting on lines, but since I have only ONE CP as I noted in my OP the minus of CP c/i.
I was an "invited" guest, so had special c/i.
Modern keycards are mostly RFID based these days so won't be wiped by 'magnetic' devices.
As long as you don't carry your keycard around in an active microwave oven you're fine!
