re.:How to connect multiple bluetooth devices to a single smartphone ( mouse + keyboard) ?
To study ADB (2 smartphones connected via usb cable or WiFi, since no microUSB 2 microUSB cable)
I can connect bluetooth keyboard for input and commands history, clicking up/down arrow key.
But most of the time I plan to spend on testing ADB, selecting C&P commands from the Internet, so bluetooth mouse should be used to select and c&p commands for tests.
Old MS Windows XP came with bluetooth software hub application to let me connect more bluetooth dev ices to work in parallel ( up to 5, if I remember correctly)
Not sure if such apk exists for Android.