Under about:unloads, you will see a list of open tabs, sorted by resource usage. You can click-spam the “Unload” button until that list is empty, or until the most resource-intensive tabs are off the list.
This does not require any third-party dependencies, and the tab will still be present on top. The site will reload once the tab is selected again.
SOMA and Outer Wilds are still haunting me like this.