Android Question Simultaneous debugging of multiple apps on the same device - is possible?

Is that necessary? They can be tested separately.
It should be obvious if App1 successfully starts App2. If it doesn't, App1 alone needs debugging.
If App2 starts but doesn't function as required, then App2 needs debugging. For that you should be able to hard-code the parameters passed into App2,

Yes, it is necessary, and it would be very useful
To understand if it is possible to do so
The debugging operations cannot be reduced to seeing 'if it starts' or not, the code can be very complex, and so if it were possible it would be a great thing
Actually I don't think there are big problems for the ide
It could be that the B4A-Bridge is not intended to work 'in parallel' with other B4A-Bridges (port number, communication, etc ...)

It is currently not possible. You will need to run one of these apps in release mode.