make sure value inputs on all nodes have an input socket.

Some nodes have value that don't have input sockets. For example the 'Difference Key' node in the compositor, has a tolerance and falloff input, but no socket. This means they can only be set by the user manually inputting a value.

To remove limitations, it would be better if all inputs on nodes had input sockets, so there values can be based on the output of other nodes, such as image nodes, noise textures, math nodes etc.