Hey dude, the features you’re referring to are part of the Procedural Foliage Volume stuff, not within the Foliage Painter Tool itself. To use Shade Radius and Collision Radius, my guess is that you need to keep using the volume (the last time I used it, you could use the Foliage Painter Tool in combination with PFV).
It’s still an experimental feature so you have to check it on in your project settings.