Is there anything I can do to prevent this from happening? I wrote my own ambient occlusion, which for compatibility with Unity shaders writes everything to _ScreenSpaceOcclusionTexture which becomes available when the _SCREEN_SPACE_OCCLUSION keyword is enabled. Unfortunately, when the SSAO feature is disabled, the shader variant with this keyword is destroyed when the project is built.
I would make your own keyword and include that keyword in a build script. Relying on Unity modifications for shaders usually is a nightmare
The problem is that I can’t embed my own keyword in the Unity shaders. I have to interact with it. I don’t want to create my own shaders for the sake of simple AO
Maybe you could modify the SSAO render feature in the URP package to still set everything, but don’t actually do SSAO