The problem is address J is now tainted and could potentially link some things together if used for future transactions with F, G, and H (if used with all 3 simultaneously, it would 100% link the original A to B tx). Additionally, it has the further weakness of not being very useful for future Darksend+'s, as it won't denominate well.

The potential "fix" that's on my mind (maybe just a workaround) is to store up these "tainted", mostly useless addresses until you have them totaling more than 1 (or 5, or whatever), at which point they could be sent to a special "redenominating" pool (and maybe you don't even need a pool, I haven't taken the time to think through all the implications of just doing it like a normal Darksend+) for recycling back to standard sized change addresses. You would still end up with one sub-1 address every time, but that's not too big of deal in my view.

Any thoughts?