Good la. Imagine your phone got hacked or stolen and someone have access to your mae app. You want them to be able to adjust your limit via mae and approve any transactions themselves via secure2u in Mae too?
By segregating, it will minimise losses in case this happen

If your daily limit is low, say 1k a day. They can only transfer max 1k/day. Minimise losses. If you loss 30k, that means u never check your bank/account for 30 days, very unlikely