The hints didn't show for me. Everything up until 14 was pretty simple, that was the first I had to experiment with. Then 15 was a straightforward development.
16 was a lot harder. I lucked into one solution, thought hard about why it was right -> solved another & eventually the rest. But I struggle to explain how to solve it, certainly the double brackets. I think 'mixing' the mechanics might help for hintless play, drop some of the earlier easy solutions to use one or two of the 'next' mechanic. and introducing more bracket solutions to build up to the difficult finale