I have a Sonoff 4Ch pro and the inching range time are 1 to 16s instead of the 0,25 to 4s announced.
Unfortunately, I really need that the inching time to be 0,25s. Can someone tell me what to do? Is there some firmware version to correct this? Can this be reconfigured somehow?
I have the same unit and wanted a 5 minute inching delay but after reading about the 16 sec maximum in the user guide I thought I would have to add external delay modules.
However when I looked at the Ewelink settings for the device you have the ability to turn inching on per channel and set it up to 59 min 59 secs. It does give you a message to say if you use the Ewelink setting don't set inching with jumpers. I wondered if it was then just a function from Ewelink but the parameters are obviously downloaded to the device as I get the required delay when pressing the button on the device as well.
Hope this solves your problem.