Excellent! Thanks for the detailed and informative response. I'll dig in to those threads and then call Powerwall support.
FYI - we've been without power for over 30 hrs now due the snowstorm in VA/DC. The Powerwalls anticipated the storm, boosted the charge to 100% and that got us through the first day but the panels are still covered by snow, so we had to vacate to find heat, power and internet!! Again, appreciate all the input and discussion.
The TL ; DR version of the very long thread linked to, is that you can call tesla to request the frequency be lowered. What they will lower it to depends on what your equipment is (solar). You generally have to give them symptoms that you are experiencing, as well.
So, you would want to call tesla tier 1 powerall support, and say something like:
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Hi, I am having issues when running on powerwall power with my APC UPS devices not operating properly, my LED lights flickering, and my Microwave making strange noises while running on battery / powerwall power. After investigating the cause, I found this is related to the powerwall frequency being 65Hz, and that this can be lowered to a number that my equipment supports. I would like to request this frequency be lowered to a number that my equipment supports to prevent these errors."
(or something close to that).
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They will have to escalate it to "Tier 2" unless something has changed, as they need to review what your inverter supports as a shutoff, etc, and if tesla did not do your solar or powerwall install, you may have to provide some more information about solar inverter model, etc.
They will take "some time" and since they are aware of this issue, should lower it for you, to something like 62hz or 62.5hz, which should correct this for you.
On a side note, wishing you the best with your situation in the weather out there.