How to provision a lookup column with enforce delete behavior as "Cascade" ?

What type of issue is this?

Question

What SharePoint development model, framework, SDK or API is this about?

💥 SharePoint Framework

Target SharePoint environment

SharePoint Online

What browser(s) / client(s) have you tested

• 💥 Internet Explorer
• 💥 Microsoft Edge
• 💥 Google Chrome
• 💥 FireFox
• 💥 Safari
• mobile (iOS/iPadOS)
• mobile (Android)
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• other (enter in the "Additional environment details" area below)

Additional environment details

• SharePoint Framework version 1.19.0

Issue description

When I tried to re-use an existing lookup Site column in list schema and set RelationshipDeleteBehavior as "Cascade" it doesn't follow that settings.
The list is created together with the lookup column but the setting "Enforce relationship behavior" of that lookup column is still unchecked (and the value is also not "Cascade")

If I create a completely new lookup column inside the list scope then the value is set to "Cascade" but there is a new uncheck setting name "Enable relationships for this column" which prevents the "Enforce relationship behavior" to be checked.

Further investigation revealed that the "IsRelationship" value of the Field schema is what controls this "Enable relationships for this column" value. But this is automatically set to true when created as Site column, and default to false when created as List column.

What's more interesting is that the provisioning engine seems to ignore this "IsRelationship" value when it is set inside list column.

So does someone know if the current SPO supports provisioning lookup column with RelationshipDeleteBehavior as "Cascade" ?