Consistency probability between observed slow extrinsic variability and simulated microlensing signals in relevant physical scenarios. The open circles (standard scenarios) and dashed lines (non-standard scenarios) represent the results from the first approach, and the filled squares (standard scenarios) and solid lines (non-standard scenarios) indicate the results using the second approach. The x-axis represents the logarithm of the M_pbh/M_star ratio and includes the three values used in the non-standard scenarios; i.e. r_pbh = −2.5, −0.5, and 1.5. We arbitrarily put the results for the standard scenarios at r_pbh = −3.4 for a better visual comparison. The source size is highlighted in blue, green, and red (see the main text).