Eligible career break: Is there an obligation to request an extension of the eligibility time window due to e.g. maternity?
No, there is merely an option for an extension of the eligibility time window under certain properly documented circumstances (such as maternity), but no obligation to do so. I.e. a PI might not want to take advantage of the extension if she/he would not be eligible yet for a Starting Grant if requesting the extension. However, it is advisable to mention the leave in the PI section so that the track-record can be judged accordingly.