After suffering from stutters when I installed the 4090 I wrote a support ticket, with the following response from Varjo:
Hello,
Thank you for contacting Varjo support, I'm sorry to see you're having issues with your new 4090.
We are aware of the issues that the 4090 cards are having with our HMDs. We are currently looking into it and will update you as soon as we have any additional information. We recommend using another GPU for now if you would like to use the Aero.
We thank you for your patience.
Regards,
Thomas
Customer Service Specialist
Varjo Technologies