using the API provided - (void)resetToFactorySettingsWithCompletion:(ESTCompletionBlock)completion; leaves the value for Accelerometer, Basic Power Mode and Smart Power Mode to what ever was last set. I would expect that as all other "factory settings" reset these would too.
Eric, good point, thanks for your suggestion.
FYI, we've just updated our iOS SDK reference - available at http://estimote.github.io/iOS-SDK/index.html - among other things, the documentation of the resetToFactorySettingsWithCompletion: method now lists all the fields that are being restored to their default values.