I actually just did what I think would be the most effective (so far), with accurate 20px size increase, and not having to rely on transparent text or plugins:
I included a repeating group within the repeating group, with a source of Calculate RandomString, length of characters based on the Current Cell’s Index:
I then Extract with Regex with a single .
Now the repeating group will be a list of characters. I placed a group of 20px in the RG, with it’s source set to ‘parent’s group text’. I don’t need to use a text element as I never need to show the text.
End result - a group of exactly 20px will appear, increasing +1 additional 20px group per line.
This was a fun challenge! It reminds me of the sort of challenges @adamhholmes was coming up with a few months back.