I think it's great that one can mark whether one knows the character and the tone.
However, now I get it more and more that I get two characters together which I know very well (like just before I got 以来) but I haven't yet learnt that particular combination. At the moment I just tell Skritter that I don't know the characters because I don't want them to just disappear before I've learnt the meaning.
Would it be possible to still add a new criteria, namely that you know the meaning, before it gets shelved somewhere?
I am happy to also just keep on marking the characters as unknown but I don't want skritter to then in the future think that I must relearn each character combination containing those characters...(可以,以后,以为, 后来,过来,起来,等等)...