How does odoo 18 not show the field by default? When I execute this code via my module, the field remains hidden.
<record id="view_customer_move_form" model="ir.ui.view">
<field name="name">opal.account.move.form</field>
<field name="model">account.move</field>
<field name="inherit_id" ref="account.view_move_form"/>
<field name="arch" type="xml">
<xpath expr="//field[@name='line_ids']/list/field[@name='tax_ids']" position="attributes">
<attribute name="optional">show</attribute>
</xpath>
</field>
</record>