Re: "iPad: Disable Onscreen Keyboard when connected to bluetooth outboard keys"
Am no expert in this area so may not be all that helpful, yet your post deserves some response. At least we get your discussion underway, providing opportunity for more expert replies.
The different third-party external keyboards may require different solutions.
You could check if this works for you.: Settings > general > keyboard > shortcut off
Else: Apple support provides an article that may have some tips:
Control iPad with an external keyboard - Apple Support
Eg: says:
" ... you can use Full Keyboard Access to control your device with keyboard shortcuts instead of the touchscreen. Full Keyboard Access highlights the item on the screen that has focus.
Control iPad using Full Keyboard Access
- Go to Settings > Accessibility > Keyboards & Typing, tap Full Keyboard Access, then turn on Full Keyboard Access.
- Navigate iPad using the following default commands.
View available Full Keyboard Access commands Tab-H
Move forward Tab
Move backward Shift-Tab
Activate the selected item Space bar
Go to the Home Screen Fn-H
Open the App Switcher Fn-Up Arrow
Open Control Center Fn-C
Open Notification Center Fn-N
Customize Full Keyboard Access
You can change the keyboard shortcuts associated with Full Keyboard Access commands, and customize the appearance of Full Keyboard Access (such as the color, contrast, and size of the highlight).
- Go to Settings > Accessibility > Keyboards & Typing, then tap Full Keyboard Access.
- Do any of the following:
- View a complete list of Full Keyboard Access commands and customize them: Tap Commands.
- Change the look of Full Keyboard Access: Tap an option below Appearance."