Just had an official response from keyshot about zbrush…
Zbrush website is owned and run by Pioxologic. What they put up is up to their discretion on how they want to run upgrades for KeyShot for Zbrush. As of recent, Maxon has instructed Pixologic on short notice to discontinue the sale of KeyShot for Zbrush. They were the only ones that had the ability to sale those type of licenses. We don’t have any upgrades for KeyShot for Zbrush. It was decided on Luxion moving forward with the decision of Maxon that anyone looking for an upgrade for their Zbrush that we can provide the Pro Subscription for $600 off for the first year but we are no longer selling perpetual licenses.
If Pro Subscription for $1,188 USD a year is too high for your business, you can check out our Personal Edition for $588 USD a year that comes that comes with less features like no Animation, no Material Graph Editor and no HDRI Editor.
So I guess Maxon are probably working on a Redshift for Zbrush alternative but zero knowledge of roadmap