Never been known to be overly safety conscious, though I am trying (very trying), however, the golden rule I got from somewhere was that if the "push through" length exceeds the "cut length" you should use a mitre gauge for push through support.
I hate to say it, but this scenario, would make even me reach for (UGH!) hand (UGH!) tools (UGH!) and a (UGH!) shooting (UGH!) board (UGH!).
If your first cut is too short... Take the second cut from the longer end... LBD
