I posted this on other threads, but I can tell you this problem has not been fixed at least on the latest brand new imac pro custom order, and with the latest mojave or even the betas. I have frequent crash to power off ("bridge OS" cited in the crash report) during startup only (or reboot) with all T2 chip functions turned off that I can do myself incl the secure boot setting off. I do not use sleep or filevault etc, so it only happens during startup so far. I have done a fair amount of, so far ineffective, troubleshooting and have a case with Apple, but Apple is still hare triggered for only to advise to do a clean install. Obviously not the solution. Unfortunately I don't feel much hope here until they replace the T2 chip hardware entirely. It has been a year since these problems started appearing on the forums and the situation isn't any better. I have limited the functionality of my computer so as to reduce, but not eliminate the problem. So in effect I have a $7000 crippled product waiting for a fix which may never come. That is the sobering bottom line.
part of one of the reports:
{"caused_by":"macos","macos_system_state":"running","bug_type":"210","os_version ":"Bridge OS 3.2 (16P52540a)","timestamp":"2018-11-24 17:17:32.92 +0000","incident_id":"324AD759-2B36-40F0-9F64-D852A528AF5A"}
"build" : "Bridge OS 3.2 (16P52540a)",
"crashReporterKey" : "c0dec0dec0dec0dec0dec0dec0dec0dec0de0001",
"date" : "2018-11-24 17:17:32.79 +0000",
"incident" : "324AD759-2B36-40F0-9F64-D852A528AF5A",
"kernel" : "Darwin Kernel Version 18.2.0: Mon Nov 12 20:25:54 PST 2018; root:xnu-4903.231.4~4\/RELEASE_ARM64_T8010",
"macOSOtherString" : "\n** In Memory Panic Stackshot Succeeded ** Bytes Traced 293920 **\n",
"macOSPanicFlags" : "0x4",
"macOSPanicString" : "panic(cpu 2 caller 0xffffff801e0da1ed): Kernel trap at ...