Ok but, in reply to that tweet, one point keccak.team make, which seems valid for non-classified cryptanalysis, is that researchers don't invest time in trying

Ok but, in reply to that tweet, one point keccak.team make, which seems valid for non-classified cryptanalysis, is that researchers don't invest time in trying to analyse ARX because the propagation of addition makes it too complicated. One thing I got from that is that ARX designs are less likely to be broken, not because they are necessarily more secure, but because ARX is often less analysed than designs which yield more concise mathematical representations.