Default Values in Shopify Connector

When mapping fields in the Shopify connector, there are some types of fields where it would be simplest to manually add in a default value that applies to all products. Examples include unit names and option labels.

Unfortunately at the moment these seem to require a value to be mapped from an attribute:

Adding in the ability to just type in "Chair Colour" or "cm" would make things a lot simpler.

Edit - in addition to the examples above, this would be useful for boolean fields that would be set to TRUE for all of our products, for example "Is Stock Tracked?"