Advice on reconfiguring with REST API

Summary:

What is the recommended action to reconfigure a line and changing an attribute value while doing that?

Content (required):

We need to be able to update (headless from commerce) previously configured line items that are past expiration, so that costing/pricing is updated to the latest.

By using a commerce action, I can make calls using REST and I thought that the following sequence of actions would work:

_reconfigureTxn _update _save

However, I need to set a boolean attribute to false, as it's used in a constraint and _save throws an error.

From the documentation, I am having a tough time picking the proper action that allows a model configuration with changing an attribute.