===== Agregar el nombre del cliente al ticket =====
/usr/lib/python3/dist-packages/odoo/addons/point_of_sale/static/src/xml/pos.xml

<code>
            </div>
            <div class="receipt-user">
                User: <t t-esc="widget.pos.get_cashier().name"/><br />
                <t t-if="order.get_client()">
                    Cliente: <t t-esc="order.get_client().name"/><br />
                </t>
            </div>
</code>

==== Referencias ====
  * https://www.odoo.com/forum/help-1/question/customer-name-on-point-of-sale-receipt-odoo-11-127096