Too much data written to preferences

[logological]

I am using v4.0.0-beta4 in Thunderbird 52.3.0. My Error Console (Tools->Developer Tools->Error Console) is constantly spammed with warnings like the following:

Warning: attempting to write 26768 bytes to preference extensions.exchangecalendar@extensions.1st-setup.nl.abe5b6a4-3eca-45a1-975e-86892396aee1.syncState. This is bad for general performance and memory usage. Such an amount of data should rather be written to an external file. This preference will not be sent to any content processes.

Is this something we should be worried about? Perhaps we should heed the warning and write this data (whatever it is) to a file rather than a preference.