For Seed Bags perhaps it's possible to extend this to not only vanilla and Natura plants but perhaps anything that uses IPlantable if that's how I believe that works. Could be neat with other mods such as pam's etc. (Issue filed as requested by @progwml6 )

It would be nice if it supports Actually Additions seeds too. ;)

Ah thanks! I couldn't think of another mod that added seeds for a second but yes Actually Additions and another one I thought of is Immersive Engineering and its Industrial Hemp

Also XyCra. . . Ugh never mind about that >.>

There are Random Things beans and color grass and Extra Utilities ender lilies and red orchids too if I remember me well.