Thanks for the suggestion
Indeed I know that's an option. I often use other forest objects as geometry sources. But that would only work well for flat surfaces or mildly curved surfaces. Wouldn't it?
I often use very irregularly shaped surfaces with gaps and holes where the patches would either stick out of the ground or get embedded in the ground, since they will only follow a flat surface or the one they were created on, giving a unnatural look. The separate grass patches used as geometry source would have to still be very small for this to work in most cases where the ground surface has many gaps/holes/ups/downs. Which brings us back to the original problem and the reason why I am using very small grass objects (only a few leaves in them)
Or can I use UV mode in the patches to make them follow the surface? Would that work? I haven't tested this extensively but in my couple of tests that didn't really work out.
Also, it's very hard to work with exclusion areas if you are using patches because the boundaries would not be as smooth as when using small (for instance) grass objects/patches. For instance, I often use one forest object for larger rocks and then a forest object to do grass & flowers & smaller stones, which uses the large rock forest object as exclusion area. The grass, flowers & stones must follow the boundaries of the large rocks closely for it to look good. That won't work very well if I'm using patches.
Also, fall off density and scale won't work as expected when using other forest object patches as geometry source since it would affect the entire patch, not just the boundary of the surface / area. Right?
Being able to have multiple items within a cluster would solve many issues for me in a very simple manner. I'm very sure others would benefit greatly from this as well! But if it's not possible I will have to think of other ways to solve it