Hello,
The problem only with SuiteTax account environment.
This is a structure I pass to NetSuiteService.getSelectValue()

GetSelectValueFieldDescription selectValueFieldDescription

{
customForm null
customFormField null
customRecordType null
customRecordTypeField null
customTransactionType null
customTransactionTypeField null
@field "taxItem" string
fieldField "taxItem" string
filter null
filterByValueList null
filterByValueListField null
filterField null
recordType vendor

recordTypeField vendor
recordTypeFieldSpecified true
recordTypeSpecified true
sublist null
sublistField null
}

It works well in Non-SuiteTax accounts, but in SuiteTax account I have an error:
INSUFFICIENT_PERMISSION</platformCore:code>
You do not have permissions to set a value for element taxitem due to one of the following reasons:

The field is read-only;

An associated feature is disabled;