Let me introduce you to my little friend: the all icons component.

All of my icons live in their own file, and all of the icons in that file are nested into this master one. If I want to add more, I just update that component in our team library. It works better than symbol overrides, but if you can swap components for each other, provided they both are in the file you are looking at.

Here’s a link to that file so you can see under the hood: https://www.figma.com/file/G1IuTMzKq0D7NhJtWaILSjxQ/Icons?node-id=53%3A213