Setting up for both Steam and Non-steam?

I’d like to create build targets that allow me to “swap” between building with OnlineSubsystemSteam support, and building with the typical OnlineSubsystemNull. Basically, during development, I’d like to be testing network code directly within the editor, and then switch to building the Steam-enabled target when I need to test it in Steam. IIRC, to properly test a Steam-enabled project, it needs to be packaged, so having a non-Steam target seems like a decent means to avoid having to wait for building, packaging and deploying just to test changes to a single line of code.

Is this possible?


Here's what I've tried:
This gives me the following error when generating project files:

Running D:/UE4S/Engine/Binaries/DotNET/UnrealBuildTool.exe -projectfiles -project="D:/Projects/SourceProjects/ProjectMyGame/MyGame/MyGame.uproject" -game -engine -progress
Discovering modules, targets and source code for project...
UnrealBuildTool Exception: ERROR: Not expecting project D:\Projects\SourceProjects\ProjectMyGame\MyGame\Intermediate\ProjectFiles\MyGame.vcxproj to already have a target rules of with configuration name Game (MyGameTarget) while trying to add: MyGameSteamTarget