this has also worked for me and the R2 (firmware 2.7.0) has now the power on state available. It also changes the layout and menu structure of the switches slightly. The wrong symbol ° has now been replaced with the correct unit kWh, so this is all fixed too.
Seems like this version should be on the official app store!
I've updated firmware to 2.7.0
eWeLink on my android is still on version 3.5.1 (from july 16th 2018) and don't have this option. I've uninstalled and installed from zero, but the version on my playstore is still 3.5.1
I'll wait for the app update on the playstore, I've never tried aptoide.com, I prefeer to wait the new version on the Android PlayStore ( hope it arrives quickly ;) )
All your messages were very useful, thanks to everyone