If you land close to 0.5ml, say inside a 10% margin, it's a negligible gap with Reta. For some other peps where precision matters more I wouldn't do it. The math: 10mg in 0.5 mL gives 20mg/mL, 1mL is 100 units so 1 unit is 0.01mL, that's 0.2 mg for each unit. A 10% slip in either the bac volume...