Greengoddess, I have very little compulsion to drink whatsoever on 6-APB, even when it's available, and this is from an alcoholic who would ordinarily plough through half a bottle of vodka in not much over an hour with not so much as a seconds thought. I struggled to get through more than a beer and a very small vodka and coke in the 20+ hours I was on 6-APB last weekend because the mix don't really appeal. Doesn't feel like the booze goes down so easily on it.
Harm reduction answer is no, you should not drink on the 6-APB at all. You should bear in mind that the chem is probably still too new for real horror stories about the effects of excessive drinking on it to have really filtered out yet, so noone can really tell you how harmful that might be. IME though low amounts of alcohol can help cut some of the jitters / excessive stimulation you might feel at higher doses, but large amounts of alcohol will at the least probably ruin the experience by cutting the positive effects too much, and is likely to be nauseating.