Your large data workflow may look like a piece of art to you, but may appear like a spaghetti nightmare to others, depending on which side of the project you're working on...
There are multiple methods you can use to signpost the process and make the schematic transformation clearer for other users, who might be collaborating on the same project, or for yourself, when you open the file next time.
To begin with, you can use the Shapes options from the + button in the workflow to add shapes, arrows and text boxes to create visual colour coding and notes that explain the function performed in a series of steps.
Secondly - every block contains the 'Notes' tab, where you can enter text with explanation about the operation performed and the purpose. When the block is closed all the blocks with notes will have a blue word bubble above them, while the notes will appear in the tooltip. The project user can also open the block's Notes tab to read or edit note text.
Another thing that will improve usability and transparency of your project is block grouping, as it will collapse multiple blocks into a single expandable group block. This method will reduce the number of items on the canvas and declutter your transformation process.
Press and hold the mouse to switch to selection mode and select multiple blocks performing some common purpose.
A group button will appear in the right corner, allowing you to group them.
This special block will have +/- buttons allowing the creator to expand the group and to make subsequent edits, or to un-group them if needed (see the screenshots below).