It would definitely be hard to use Anki for conceptual learning that requires fresh problems to prevent memorizing answers. One could link to an outside site keyword categorizing problems matching specifics, I suppose..

Really though a lack of spaced repetition on practising conceptual problems is just as noticeable as the lack of spaced repetition on factual learning. Very few fields are so perfectly structured that you get practices on their earliest levels by doing later levels and then working in the field, i.e. plenty of mathematicians admit they no longer do arithmetic well.