Update: After having happily using my MacBook with High Sierra for some time, I decided to give Mojave another shot (10.14.5 was installed). The problem immediately returned :(. I cannot upgrade to Catalina because my company's IT says it is not yet compatible with all our software.

Update: I managed to downgrade my machine to High Sierra, and that seems to have resolved this issue.

Does creating /var/log/do_dnserver_log still work in 10.13 (High Sierra)? I'm having problems with distnoted using lots of CPU. I touched /var/log/do_dnserver_log as root, chmod 666'd it, and rebooted. I'm still not getting any log messages written to it.

Update: The logic board replacement did not solve the problem. I downgraded from Mac OS Mojave to High Sierra, and things appear much more stable now. I'm going to give this some more time before I count the issue as resolved, though.