Upgraded Mac (Darwin 19.6.0) to Boinc 7.16.11 and added cc_config.xml:

<cc_config>
<device_name>my-device-name.local</device_name>
</cc_config>

Boinc started up and ran as expected, but log reads:

Wed Sep 9 00:42:01 2020 | | Unrecognized tag in cc_config.xml: <device_name>
Wed Sep 9 00:42:01 2020 | | Starting BOINC client version 7.16.11 for x86_64-apple-darwin
Wed Sep 9 00:42:01 2020 | | log flags: file_xfer, sched_ops, task
Wed Sep 9 00:42:01 2020 | | Libraries: libcurl/7.58.0 OpenSSL/1.1.0g zlib/1.2.11 c-ares/1.13.0
Wed Sep 9 00:42:01 2020 | | Data directory: /Library/Application Support/BOINC Data
Wed Sep 9 00:42:01 2020 | | OpenCL: Intel GPU 0: Intel(R) UHD Graphics 630 (driver version 1.2(Jul 6 2020 11:56:19), device version OpenCL 1.2, 1536MB, 1536MB available, 230 GFLOPS peak)
Wed Sep 9 00:42:01 2020 | | OpenCL CPU: Intel(R) Core(TM) i7-8700B CPU @ 3.20GHz (OpenCL driver vendor: Apple, driver version 1.1, device version OpenCL 1.2)
Wed Sep 9 00:42:01 2020 | | Version change (7.16.6 -> 7.16.11)
Wed Sep 9 00:42:06 2020 | | Host name: same-old-wrong-name.local

<cc_config>
<device_name>my-device-name.local</device_name>
</cc_config>

This isn't a good cc_config.xml file.

cc_config.xml uses the following structure:

<cc_config>
<log_flags>
....
</log_flags>
<options>
....
</options>
</cc_config>

See https://boinc.berkeley.edu/wiki/Client_configuration for more information.

So in your case it's:

<cc_config>
<log_flags>
</log_flags>
<options>
<device_name>my-device-name.local</device_name>
</options>
<cc_config>

---

Thanks. That works. I'm embarrassed (again).