Modes and Routines is certainly a feature on your phone, so have a play with all the options yourself and see if you can make one up. It's a good way to familiarise yourself with your device.
Ahhh well. Your idea is a good one nonetheless. Maybe you could send a request to Samsung and ask them to design a widget that could switch between SIMs. You can do this via your Samsung members app. Just head to the Support section and tap on Ask questions.
