I've noticed that a lot of people have already asked for this, but those might land on having the need for more information.

I'd like to see a feature like this added, because the predictions are wrong so often! I pull a line which I want to be straight, may have wiggled slightly and GN5 in some cases recognises it as a curve.

A ruler in GN5 would also just help you with sketching up stuff real quick, like a sheet or so without having the need to either import your own paper that has this or rely on the prediction system and having to do micro-adjustments all the time.

It would also just be very useful if you simply work with stuff, where measurements have to be accurate.

In some ways you can even use the ruler AND the prediction system, an example would be to just draw a few lines which the prediction system had done and later you check with the ruler how long those lines actually are (if necessary)

Please take this into heavy consideration.

I hope this suggestion finds you well.