Adding (which is planned to conduct middle term) Curve app with all cards installed to one further device + adding my Curve credit card to same device will it work seamlessly?
At current point of time Curve is already used on one device (both app and credit card in Apple Pay wallet).
You can add Curve card on unlimited devices as payment *Pay (Apple Pay, Gooogle Pay, Fitbit Pay, Garmin Pay, Samsung Pay, Huawei Pay, … ) and pay simultanously via any of them.
Cad can be addded to *Pay also manually (number, date, cvc) … no app required … it will request sms/email verification.
Curve App can be logged only on one device. Every new login - logout the previous.