License should work without email
What is the feature you'd like to have? In a malware VM, I would prefer if my email was not present. It would be nice if the license did not require a valid email address and just relied on the serial and signature.
Is your feature request related to a problem? Anonymity
Are any alternative solutions acceptable? An alternative solution would be to load the license every time. However, BinaryNinja is nice and saves it because most users do not want to locate their license every time. If there could be an option to not write the license anywhere else on disk, one could set their email in the license, load it, then change the email back. This would save the step of having to also navigate to %APPDATA% and delete the copy BinaryNinja wrote.
For another alternative solution, you can run binaryninja with the BN_LICENSE env var set to the contents of the license file, and the license won't be written to disk. This does still require the email, but having it in an env var might be preferable.