How to prevent Chrome (macOS) from removing manually installed extension on Chrome updates?

I’m using 1Password 7 (the very last pre-subscription version) which requires a »classic« (deprecated Manifest 2) extension. As the extension is no longer available through the Chrome Extensions Store, I have to manually install it, by loading the unpacked extension (which I place in ~/Library/Application Support/Google/Chrome/Default/Extensions/) via chrome://extensions in Developer mode. The annoying problem is that with every Chrome update the extension gets removed and has to be reinstalled manually ... and we all know the update frequency of Chrome. **Question is: How to prevent Chrome from deleting the extension?** *(Currently using Chrome Version 131.0.6778.109 (Official Build) (arm64) on macOS 15.1.1)*