I'm sympathetic to this, but I think that empty parameters adding a ? is actually a good behavior.

If someone really wanted to omit the query string, they would just pass nil parameters. There is indeed a functional reason why someone would want to append a blank query string, and that's to invalidate cache. I couldn't tell you if anyone has specifically used this feature, but I wouldn't want to introduce a potentially-breaking change without a clear advantage.

Right. That's one reason - generally I would add a timestamp param or similar to clear cache.
Where this behaviour of the empty array was getting me, was I was passing mutable array that may or may not have elements.

I don't particularly mind as it wasn't breaking anything for me, It would just execute this code path that had unnecessary calculations.