New User Trying to get my head around how the sytem operates

Just had my old boiler and Hive system replaced. I now have a Wireless receiver, Wireless Thermostat and around 50% of the radiators have smart thermostats installed.

When I open the Tado app on my phone there are buttons for Hot Water, each of the Smart Radiator Stats and the Wireless Stat but there is no button for the Wireless Receiver (It is shown in the list of connected devices). Is that correct?

I can individually schedule each of the stats and the hot water.

My assumption is that any stat can call for the heating based upon its own schedule. I.E. most of the radiators are scheduled to come on at 07:00 off at 09:00 and back on at 17:00 until 22:00. However I have 2 office radiators that are scheduled to come on at 09:30 and off at 16:30. Am I correct in assuming that and that there is no master schedule that overrides everything else?

Thanks in advance for any advice