Let each tab use a different IP address with Proxy Per Tab.
Simply load up all of your proxies (you can add them to the settings individually or import a csv file). Then you can set the browser to randomly use a new proxy for every tab, choose a direct connection, or use your system settings?
Sound complicated? It’s not. The random proxy setting will take care of all of the proxy selection for you, so you can focus on getting your work done!