It seems that in the above study, 14 out of 14 were doing so from their normal diet. These were subjects who exercised from 2.5 to 10 hours per week.
I’m not saying that supplementation of up to 50 mg/day (but not above, and if using several products one should check on this) cannot be a good idea. But rather that a fear that a loss of a few percent of absorption is somehow going to be critical is just not reasonable. It is natural and we are adapted to consuming them at the same time. IMO, no one should screw with what they consider their optimal timing for protein intake for the sake of their zinc supplement delivering an unnecessary further increment. It is not as if the situation is that marginal.