KDVR3 FW 2.05 was released in Aug 2019 (your rig was prior). It is current as of today, Oct 2020 (for new type boards only. 1.04 or earlier is good for earlier boards).
Please coordinate with Support to send them in. I assume a bunch together would be fine (easier for the programming person for sure).
**Earlier boards with FW 1.04 and earlier should NOT be sent in,,,, they are OK.
**TO CLARIFY; Only send in the newer revision of the board with 2.00 thru 2.04 firmware, OR glitchy Firmware reporting like 00.10 etc that changes with each power cycle or query to read FW.
At turn-on of the K3, long press Menu and you will see the current MCU FW of the radio... Rotate VFO A fully clock-wise and read the "dr 02.xx" number to see the DVR Firmware.
*OR* look at the board; With the top cover off you can look down in and see;
Old DVR has the big electrolytic capacitor near the mounting standoff, don't send this in.
New DVR has the big capacitor near the connector, Send these in.
You are responsible for shipping both ways, programming is Warranty.
Keith WE6R Elecraft K3 Tech