SUMMARY
I use /dev/sr0 for digitizing discs stored in a self-storage facility for over a decade; currently using /dev/sr1 for ddrescue the discs that succumbed to bit rot with brown edges.  In ~/.config/k3brc I have sr1 commented out, since k3b hangs trying to read a disc with bad sectors, dmesg shows the read errors generated. it just doesn't give up trying to read bit-rotten discs. K3b opens with both drives listed. I highlight sr0. When I open Copy Medium, it hangs on the first page trying once again to read a defective disk on sr1, ignoring  ~/.config/k3brc which has that drive commented out. Eventually, over half a minute later, I choose Only Create Image and get into the Image tab where the Source Medium is always the wrong drive. I have to manually select sr0 with a good disc. With the Source Medium showing the DVD title with upper-case first letters of each word, while the Write Image window displays the same title all lower case.
Bug: K3brc defines only the internal disc drive, yet k3b ignores that setting and displays info on both drives. This is incorrect, clearly violating the Principal of Least Astonishment. The manual was last touched over a decade ago; a search for k3brc returns empty results.

STEPS TO REPRODUCE
1. Open K3b on a box with two DVD drives. Observe both drives in the upper-left window.
2. Choose the Copy Medium from the lower right.
3. 

OBSERVED RESULT
K3b hangs for over half a minute trying to read the wrong disc before opening the medium copy dialog.

EXPECTED RESULT
Just like audio CD ripping which ignores the bad disc in the other drive.

SOFTWARE/OS VERSIONS
KDE Plasma Version: 5.27.11
KDE Frameworks Version: 5.116.0
Qt Version: 5.15.13

ADDITIONAL INFORMATION
I've never used two drives before, so I don't know if it ever worked correctly.