The current public beta version of EagleFiler is compatible with the beta for macOS 12. You can sign up below to be notified when new beta versions are available and download them from within the app.
The beta release notes are available in the Software Update window and also in the “Version History” section of the manual (in the Help menu).
We do not recommend using a macOS beta on your main Mac, as there may be bugs that we have not had time to, or cannot, work around. With that said, we do welcome bug reports so that we can investigate any bugs and report them to Apple or try to develop workarounds. Please submit any feedback or bug reports via e-mail, rather than posting here.
I recommend updating from the release version to the beta (using the setting at the top of this page) before updating to Monterey. If you are already on Monterey, I can send you a download link for the current beta.