old_contents: # Copyright 2020 KMEE
  # License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl).
  
  from odoo import models
  
  
  class AccountChartTemplate(models.Model):
      _inherit = 'account.chart.template'
  
      def try_loading_for_current_company(self):
          if self.currency_id == self.env.ref('base.BRL'):
              for template in \
                      self.env['l10n_br_account.tax.template'].search([]):
                  template.create_account_tax_templates(self.id)
          return super().try_loading_for_current_company()
  
new_contents: # Copyright 2020 KMEE
  # License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl).
  
  from odoo import models
  
  
  class AccountChartTemplate(models.Model):
      _inherit = 'account.chart.template'
  
      def try_loading_for_current_company(self):
          self.ensure_one()
          if self.currency_id == self.env.ref('base.BRL'):
              for template in \
                      self.env['l10n_br_account.tax.template'].search([]):
                  template.create_account_tax_templates(self.id)
          return super().try_loading_for_current_company()
  
      def load_for_current_company(self, sale_tax_rate, purchase_tax_rate):
          super().load_for_current_company(sale_tax_rate, purchase_tax_rate)
          # Remove Company default taxes configuration
          if self.currency_id == self.env.ref('base.BRL'):
              self.env.user.company_id.write({
                  'account_sale_tax_id': False,
                  'account_purchase_tax_id': False,
              })
  
subject: remove defaults account_sale_tax_id and account_purchase_tax_id in l10n_br we config taxes using fiscal definition object