When importing a CA certificate, it is possible to import like this:
set pki ca "My Root Certificate" certificate BASE64DATA
This works fine, and saves fine.
However, when saving the config and restarting, the config fails to load, since it is saved like this, which seems to be invalid:
pki { ca My Root Certificate { certificate "BASE64DATA" } }
It is also possible to to use dots when importing a certificate - not sure if that is causing problems.
It seems like some input validation is missing.