While not 100% sure for an Apple Watch, I found the below in the FAQ section. Looks like you just need to change your plan type. https://support.bell.ca/mobility/rate_plans_features/what_is_bell_smartpay?step=3#step3Am I able to pay my device in full...
Sorry to say the standby timer is not a setting that can be changed and it at 4 hours to help prevent burn in. I know you're not the first person to ask about this. I'll be pass along to our TV Product team to see what might come in the future.
