"SAVINGS
Balance subject to 3 day withdraw waiting period, STEEM Dollars currently collecting 0% APR."
That it states "currently collecting 0% APR" implies that these values could be changed to be >0 and thus the function for compound interest is built into the system, yet seemingly not activated. Obviously Dan or Ned would need to clarify.
SBD collects interest regardless if you hold it in the savings or not (as long as the witnesses have set the parameters of the blockchain to do so). The statement "currently collecting 0% APR" is just informing that currently SBD do not accrue interest.
I agree that the wording is confusing.
BTW Dan is no longer part of Steemit Inc. He resigned his position as CTO several weeks ago.
I knew he had resigned, but I figured if anyone would know it would be Dan or Ned.