Was unaware that is all thats needed to transfer a number. Thought about porting a number to Twilio, then to have 2 phones which one would have to pay for and just switch the call forwarding.
I'll check out the sim card solution, thanks for the info!
By taking out a sim card you don't remove the risk of physical damage to your phone. By replacing a $10 phone with a $600 phone you can eliminate the risk.
I think the idea being presented is to physically own both devices, and simply swap the SIM card from device to device as needed.
I'd imagine that swapping (micro)SIM cards gets quite old quite fast. Heck, just rebooting phones all the time would be annoying imho.
SIM cards/trays are not physically accessible and sturdy enough to make that practical as a daily activity.
A "family" plan across both phones is more likely solution.