Editing <target> of source language XLIFF without modifying <source>

[PriyaYashu]

We are using Weblate 4.9.1 with XLIFF 1.2.

Our XLIFF files are structured like this:

Add.property Add new property

In our application:

is an immutable translation key. is the editable text.

We have:
messages.en.xliff
messages.en-US.xliff

where both files have the same values, but different values.

Our goal is:
Allow translators to edit only the element in both messages.en.xliff and messages.en-US.xliff.
Never modify the element.

What we have tried
XLIFF Translation File
XLIFF with Gettext extensions
Monolingual base language file configured
Monolingual base language file removed (bilingual mode)
Edit base file enabled and disabled

Current behaviour
messages.en-US.xliff is editable and works as expected.
messages.en.xliff is treated as the source language.
If Edit base file is disabled, the English translation is read-only.
If Edit base file is enabled, Weblate also rewrites the element to match the edited .

Example:

• Add.property
• Add new properties

• Add new properties
• Add new properties

Question

Is this workflow supported by Weblate?

Can Weblate be configured so that, for the source language XLIFF (messages.en.xliff), only the element is editable while is always preserved?

Or is this not supported