MQTT + Sonoff + Curtain

I set a Sonoff 4ch pro with Tasmota in order to use it with the engine of the window Shading cover on the terrace.
I installed Mosquitto on my RPi and a two binary switches (one for each channel) in order to test the interlock mode of the Sonoff: everything is working fine.
(I used two bulbs just as test! )

Now, I really missed the parts:

  • How I say to Sonoff channel_1 :“hey, give power for 65 seconds in order to open all the cover”?
  • How I say to Sonoff channel_2 :“hey, give power for 75 seconds in order to close all the cover”?
  • How con I ask to Sonoff: “how many % is the cover opened/closed ?”

The cover can be used with a couple of buttons too, so I suspect it’s not always possible to know the status of the cover? Right ?

Thank you, very much: I am totally lost here.