Beta test build with debug option.

I want to test a new feature in my watchApp on a real device (a Fenix5) using the Beta Test release option. 

There used to be a build option in the project export process that offered the option to run in debug mode, but it's not there any more and the build command is defaulting with the -r compiler option.

Is there any way to suppress the -r option in a beta release?

[EDIT]

I can see a debug option in the "build for device" - but that is for a side load and in a side load, I don't get to test Settings changes, which is part of my test plan.

I have tried to suppress the -r option by editing  the  tasks.json, but it ignored my 

"compilerOptions": [ "-w", "-y", {mydeveloperkey}" ],