It’s probably better to consider that an advanced option, and try a more straightforward approach first.
If you want to change the shifted character on a key, look in the sidebar for the link to the Keyboardio forum; there are discussions on the forums about how to do it, and friendly folks there who can answer questions.
I’m wondering why that is, because I certainly want to alter many shifted characters in my setup, and the instructions given its use are not all that intimidating. Are there issues about it that mean it should be avoided - I’ve been seeing it proposed pretty freely in the forums? Also I couldn’t find the quoted discussions of simpler methods.
I think the “more straightforward approach” would be LSHIFT(4) in the keymap, on a symbol layer. So to input $, you’d press something like Left FN + 1 instead of Shift + 4 (assuming that we want to move $ to the position of the 1 key).
That’s not unreasonable. I may do that until ShapeShifter is more stable, but I would certainly prefer it as intended with a more stable ShapeShifter. Considering it’s looking like I’m going to be using a lot of plugins and don’t know much about coding, probably better if I play it safe there!