Thank you for the follow-ups here han, I was away from a computer myself for a while so can apologise in turn for a late reply. I am slowly filling in the gaps to your method and it is, as cherdano says, very interesting. If I may repeat the same trick as with Quantumcat's system, do I have it all correct here now?
1D - 2C
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X = 4+ spades
2D = 4-5(bad 6) hearts, nf
2H = 5+ hearts, f1
2S = 5+ spades, f1
2N = good diamond raise?
3C = 4 hearts, gf
3D = weak diamond raise?
3H = 6+ (good) hearts, ~7-9
3S = 6+ (good) spades, ~7-9