In low stakes live tournaments I think push or fold is optimal strategy.

I sometimes play £30+3 10 man SNGs at local casino. Starting stacks 1000 chips, blinds 25-50 and 15 minute levels. Think I have played around 10 and don't remember every doing anything other than all in, check or fold. The table rarely has an average M of over 15. I guess you can call with small pairs in late position during 1st blind round, other than that though its fold or push.