I'm just starting but it seems it would be more helpful to learn the symbols in relation to their phonetic sound, not their "romanization". Which I had to look up just to understand.
Since I'm sure the spelling is super important, maybe make an intermediary step to learn that?
When I hear wau and click wa but the answer was wo it gets frustrating after a few times. That frustration was part of why I haven't touched the alphabet learning in a week or so. I think a redesign would be best, but maybe I'm the only one.
Many are of the same opinion. However, I hope you don't let that stand in the way of your learning Korean. I would suggest (as others have as well) learning the alphabet (hangul) on youtube or some other website. https://www.duolingo.com/comment/24886787 has at least 2 posts with lists of alternatives.