Just to follow up on my progress. I've been testing on real devices using Xcode but decided to try the simulator and tried an iPhone 15 where I noticed the "Home indicator bar" so searched on how to hide it and came across this post:
https://www.construct.net/en/forum/construct-3/how-do-i-8/include-cordova-plugin-172165
Which lead to these instructions:
https://www.construct.net/en/tutorials/building-mobile-apps-locally-21
I got Cordova installed
Then cordova prepare
(had to install several dependencies to get this to work)
cordova requirements
showed no issues
cordova build
failed with "Value for SWIFT_VERSION cannot be empty"
Figured out that I needed to open /platforms/ios/<project name>.xcworkspace, go to Build Settings and change "Swift Language Version" from "Unspecified" to "Swift 4.2" (similar to above post)
cordova build
succeeded so reopened the .xcworkspace file again and managed to test the app OK again.
Then realised I'd not read that original post thoroughly and hadn't installed:
github.com/chipbell4/cordova-plugin-hide-home-indicator
(or updated config.xml to include a reference to it!)
Once that was installed and I'd updated config.xml, cordova prepare
and cordova requirements
ran OK
But cordova build
failed with the same Swift version error plus another "'IPHONEOS_DEPLOYMENT_TARGET' is set to 11.0, but the range of supported deployment target versions is 12.0 to 17.2.99" error. So back to the xcworkspace file in Xcode to fix the Swift version error again. Haven't needed to fix the other error yet - the project's building OK on the simulator.
And the result? I think it's working - I'm using the mouse to simulate clicks and I think iOS shows the indicator bar when it detects mouse activity. I can also control my game with a keyboard in which case the bar isn't show - so I'm hoping that's the case when using a real device with touch.
Maybe a "Hide home indicator" option in the build settings? (Godot has had this for a while).
Also wondering whether the build process needs updating to address some of the other issues I've described in this thread?