Does an aftermarket remote start system fob replace the need for factory fob

I am installing a remote start on my 2013 Prius. I was originally only going to install the bypass device that allows my to click 3X on the factory fob to remote start the vehicle but then realized that it appears to be fairly easy to add a remote system to the bypass that gives a range of several hundred feet to start the car remotely. These fairly inexpensive systems come with their own remote control. I am unclear whether or not these remotes will replace the need for the factory remote. This is an issue since I am in the process of purchasing a couple of additional factory fobs when it occurred to me that I might not need to if these aftermarket remotes effectively replace the factory ones.

Can someone please tell me how this works with the Prius?

Thanks.