Comparison of the results for three stars (displayed in different colors: orange for Sk -67°167, red for LMCe 078-1, and blue for Sk -71°41). We compare our default runs (darkest shade, Tables B.1 and B.2) with two different test runs: in one case we set v_micro as a free parameter (middle shade; labeled ‘vmicro’), in the other case we fix the CNO abundances to the LMC baseline values (lightest shade; labeled ‘cno’). Each bar indicates the 1σ range of parameter values, the dot indicates the best fitting model. A free v_micro does not result in significant changes in abundance. Furthermore, we see that both T_eff as well as wind parameters are robust against changes in v_micro and abundance.