I would recommend sending an email to Krell's service department. I am confident that Patrick (or someone else there) will honestly try to help with the issue before they recommend to have the units sent to them.
I have for sale my dCS Vivaldi Transport in silver finish and in mint condition, latest software version.
Asking price is USD 19.5k plus shipping or best reasonable offer.
Please contact me with any questions or to discuss pricing.
I have been thinking of trying Roon (with my Synology 713+) as well, but I had read (in the instructions) that Roon recommends NAS with 4GB of RAM, while my unit has just 1GB. Also, would need to add SSD...., so these requirements have slowed down the timing of my experiment a bit. Any...