The single note polyphony issue was addressed in another thread. Can’t remember where though. It made some degree of sense (something to do with phase issues), but none of the other digital polysynths I’ve played have the same behaviour. I think it should be a switchable option, per sound if possible.
It’s not “user error”, but it sometimes is up to the user to think of a fix. The clicking isn’t always due to the same note being repeated. The solution depends on the kind of sound you’re trying to make, oscillator retrig, envelope parameters (including envelope retrig!), and probably a lot of other stuff. It’s a very versatile synth engine, and as such the default settings aren’t always appropriate.
Put it this way, if Elektron introduced small fades for everything so clicks were eliminated, what would you do if you actually wanted a click at the beginning of a sound?