That system certainly removes the fog generated by the classification terminology. It cuts out the intermediate step of asking "is this a true X Class conditional? A question that serves no useful purpose other than giving exegetical commentaries something to talk about. Keeping the “if” clause and the “main clause” separate also has the benefit of covering cases where we find somewhat abnormal syntax. For example:
2Cor. 2:2 εἰ γὰρ ἐγὼ λυπῶ ὑμᾶς, καὶ τίς ὁ εὐφραίνων με εἰ μὴ ὁ λυπούμενος ἐξ ἐμοῦ;
more on that passage:
http://discourse.textkit.com/t/reading-pauls-2nd-epistle-to-the-corintintians/14010/1