Update Document REST API - how to merge attributes instead of replacing all?

[sp88011]

I'm playing around with the REST API, specifically the "Update document endpoint", see Postman.

The default behavior when updating attributes for one/or more nodes is that the attrs object we pass to the server will replace all the existing attributes.

Is there a way to merge attributes instead? Basically only replace attributes that we pass to the endpoint while keeping all others in place?

I could work around it by fetching all existing attributes first before updating them, but it doesn't seem possible to fetch specific nodes. I would have to fetch the whole document and then go from there which seems burdensome for such a simple operation.