This is true, but it takes an age to self discharge if you have your battery set to discharge after the maximum 10 day period that getting into the period that can (not necessarily will but can) degrade your battery. Two or Three days before self discharge is a good setting.
You could well be right and if so my apologies. I have 7 aircraft running from my installation of DJI GO 4 so I may well have missed that and assumed it was in all configurations, The Spark is not my most used RPA.. I plead old age and senility.
I'd still be popping the battery in and hivering the charge down to 2 lights flashing third after 3 or so days none the less.