So I tried doing this:
<record model="ir.ui.view"
id="sale_order_email_scheduled_collection_form">
<field name="name">sale.order_email.scheduled_email.form</field>
<field name="model">sale.order_email.scheduled_email</field>
<field name="inherit_id" ref="email_template.email_template_form"/>
<field name="arch" type="xml">
<xpath expr="//h1" position="after">
<h2>Test Foo</h2>
</xpath>
</field>
</record>
What ends up happening is that the form becomes plain without grouping. If I however straight up copy the email_template form instead the groupings work fine. I.e. this:
<record model="ir.ui.view"
id="sale_order_email_scheduled_collection_form">
<field name="name">sale.order_email.scheduled_email.form</field>
<field name="model">sale.order_email.scheduled_email</field>
<field name="arch" type="xml">
<form string="Templates">
<sheet>
<div class="oe_title">
<label for="name" class="oe_edit_only"/><h1><field name="name" required="1"/></h1>
<group>
<field name="model_id" required="1" on_change="onchange_model_id(model_id)"/>
<field name="model" invisible="1"/>
</group>
</div>
<div class="oe_right oe_button_box" name="buttons">
<field name="ref_ir_act_window" invisible="1"/>
<button class="oe_inline oe_stat_button" name="create_action" type="object"
attrs="{'invisible':[('ref_ir_act_window','!=',False)]}" icon="fa-plus"
help="Display an option on related documents to open a composition wizard with this template">
<div>Add<br/>Context Action</div>
</button>
<button name="unlink_action" type="object"
class="oe_stat_button" icon="fa-minus"
attrs="{'invisible':[('ref_ir_act_window','=',False)]}"
help="Remove the contextual action to use this template on related documents" widget="statinfo">
<div>Remove<br/>Context Action</div>
</button>
<button class="oe_inline oe_stat_button" name="%(email_template.wizard_email_template_preview)d" icon="fa-search-plus" string="Preview"
type="action" target="new"
context="{'template_id':active_id}"/>
</div>
<notebook>
<page string="Content">
<label for="subject"/>
<h2 style="display: inline-block;"><field name="subject" placeholder="Subject (placeholders may be used here)"/></h2>
<field name="body_html"/>
<field name="attachment_ids" widget="many2many_binary"/>
</page>
<page string="Email Configuration">
<group>
<field name="email_from"
placeholder="Override author's email"/>
<field name="use_default_to"/>
<field name="email_to" attrs="{'invisible': [('use_default_to', '=', True)]}"
placeholder="Comma-separated recipient addresses"/>
<field name="partner_to" attrs="{'invisible': [('use_default_to', '=', True)]}"
placeholder="Comma-separated ids of recipient partners"/>
<field name="email_cc" attrs="{'invisible': [('use_default_to', '=', True)]}"
placeholder="Comma-separated carbon copy recipients addresses"/>
<field name="reply_to"
placeholder="Preferred reply address"/>
<field name="user_signature" string="Author Signature (mass mail only)"/>
</group>
</page>
<page string="Advanced Settings">
<group>
<field name="lang"/>
<field name="mail_server_id"/>
<field name="auto_delete"/>
<field name="report_template" domain="[('model','=',model)]"/>
<field name="report_name" class="oe_inline"
attrs="{'invisible':[('report_template','=',False)]}"/>
</group>
</page>
<page string="Dynamic Placeholder Generator">
<group>
<field name="model_object_field"
domain="[('model_id','=',model_id),('ttype','!=','one2many'),('ttype','!=','many2many')]"
on_change="onchange_sub_model_object_value_field(model_object_field)"/>
<field name="sub_object" readonly="1"/>
<field name="sub_model_object_field"
domain="[('model_id','=',sub_object),('ttype','!=','one2many'),('ttype','!=','many2many')]"
attrs="{'readonly':[('sub_object','=',False)],'required':[('sub_object','!=',False)]}"
on_change="onchange_sub_model_object_value_field(model_object_field,sub_model_object_field)"/>
<field name="null_value"
on_change="onchange_sub_model_object_value_field(model_object_field,sub_model_object_field,null_value)"/>
<field name="copyvalue"/>
</group>
</page>
</notebook>
</sheet>
</form>
</field>
</record>
Why is my inheritance not working as expected?