Hi Brett,
With ZT-HE, you should be able to print almost any PLA at 200 - 210º, maybe even 195º. At 235º I'm afraid you may find raft and support removal to be difficult. If you're not using ZT-HE and using the Zortrax hot end instead, most brands of PLA will click like crazy and there's nothing you can do except raise the temperature.
We have found that some of our ZT-HE nozzles were coming from the factory with tiny metal chips in the orifice from machining, so recently we have begun poking all of them with a 0.4mm wire before shipping.
Other causes of clicking can be too much pull/drag/tension on the filament due to rear spool mounting and friction, or worn threads on the feeder bearing shaft screw.
A very few brands of PLA, like Taulman InPLA and Polymaker PolyPlus, do seem to give clicking problems at low temperature no matter what, but the ICE PLA you're using specifically says that it prints at low temperatures.
