The documentation here lists these options:

• --save-baseline <name> will compare against the named baseline, then overwrite it.
• --baseline <name> will compare against the named baseline without overwriting it.
• --load-baseline <name> will load the named baseline as the new data set rather than the previous baseline.

But there is also --baseline-lenient which I found through this issue, and it's really helpful especially for CI builds! The code seems to already include it, maybe I'm visiting the wrong site?