'Last Event Sensors' (fsptws inva lbp lccfc lccfi lcctc lfspt lmsc lpsc lmsc) are also available as DELTAs to 'Reboot Time'

Thanks to the feedback of @karliwalti (#2 & #4) the Timestamp related Sensors are now additionally available as 'deltas' - means the sensor value returned from the API will be subtracted from the reboot time value.