I'm exchanging messages with Ownership on the new variable charging feature - and continue to press that they amend the recommended charging practice in the Owners manual to explain how and why to use the new variable charge feature.
The current rules are to charge to standard almost all of the time, leaving the car plugged in whenever possible - and to only use max range charges infrequently. This is pretty simple.
If the new variable charge feature is intended to help when plugged into more expensive public chargers and cut off charging when less than a full "standard" charge is needed, then the feature is something that won't affect the overnight charging practices - and would be useful to help save $$$ when charging in the wild (i.e. not at home or on a supercharger).
BUT, if this feature was implemented to encourage owners to charge lower than 90% overnight (such as with the 7 step process listed above), then the recommended charging practice will be more complicated than the original simple rules.
So far, the feedback from Tesla Ownership is that the Model S batteries are never charged to 100% of charge (as defined by the battery manufacturer), even with a max range charge. Decreasing the overnight charging to under 90% of capacity (which could be more than the 90% we see in the car, because the reported 100% charge in the car, isn't 100% of the capacity of the batteries) helps to extend battery life - and that further decreasing the charge level will have a much smaller benefit. One of the statements in the last message was "the difference between a vehicle always charged to 90% vs. a vehicle always charged to 80% should be negligible".
Tesla should update the owners manual and the 4.5 release notes to provide more clarity on this new feature - and how it should be used.
Based on the information I've received from Tesla so far, it appears charging overnight to 90% is still the recommended practice - and the ability charge to lower levels won't have any significant benefit on the battery life.
And if this is NOT the case, then Tesla should make this clearer - and soon...