Yaml Environment Variables in Silverstripe 3

Questions
1

Silverstripe Version:
3.7.3

Question:

Is there a way in Silverstripe 3 to include environment variables in the yaml config files, in the same way as the backticks does in 4?

2

I recently discovered that you can’t :frowning: except in Injector config. There’s a note in the docs about that limitation but it doesn’t say why.

Perhaps you can use Injector config to set a property on any class though? Injector remains a bit of a mystery to me.

Edit: I got this question flipped around, sorry! Not sure about SS3.