Custom Field on Trello node

The idea is:

An option to manipulate the Custom Fields directly from the Trello node

My use case:

Adding/deleting a custom field on the board, manipulating the values for a custom field on the card.

I think it would be beneficial to add this because:

Custom Fields are now available for all free Trello users. Hence, adding this feature to the official Trello node would be nice.

Any resources to support this?

Getting started with Custom Fields
CustomFields REST API
Manipulating Custom Fields on Card

Are you willing to work on this?

Sure. I am currently using raw HTTP Post commands. So might have a look at porting into the official node.