Think First
Armchair pilots may have a little trouble drawing 'absolute' lines here. So help me, I cannot envision an experienced PIC having any trouble: If it does not look, smell, or feel right, including all relevant sub-systems at any point before that 'almost magic' V1, you simply do NOT go flying until the engineering experts hand you a little slip that says, "OK to Fly." To put it another way, '... cautious pilots become senior pilots; the rest are already dead...'