I can see how you want Square to sync to QuickBooks Online (QBO), dg311.
For now, the feature needs for sales tax to be turned on in order for the sync to work. As you've mentioned that a case has already been created with the issue, I would also recommend contacting Square to check with them if they can give suggested workarounds with your case.
To give you more information on how Square works with QBO, please read this article for more information: Sync Square With QuickBooks Online.
For reference, you can also set up and use automated sales tax in QuickBooks Online.
Keep in touch if you have any other questions about the sales tax. Remember, if you need any help we're always right here to assist you.