It would be great if I can use the rate to set a condition to send to my circuit network.
Maybe set the input rate as negative values.

The tool only calculates the values when you select and release. It sounds like what you're asking for is something more dynamic. Note that the tool only calculates the theoretical maximum rates.

If you want a way to copy and paste values from the tool dialog into a combinator, that could be possible.

yes. copy the information from the dialog should be enough. Right now I am using crafting combinator to read the ingredients. I have to calculate the input and output by myself. And paste it to a constant combinator using https://mods.factorio.com/mod/PasteSignals since crafting combinator is very UPS unfriendly. If this mod can have this feature, it will be very helpful.