Something you can try, and it's what I do: join a freeroll, then click auto-muck and sit out. Then sit out of the game until the add-on at the break. I'm playing in the $300 GTD FR and the add on is .45 for 5K stack.
Usually, I don't play a hand and I'll have ~400 chips left from my starting stack. So, when I take the add-on, it brings me up to 5400 chips. With blinds at 75/150, I have 36 BBs to play with, which is enough for me. Sometimes I will play a big hand like AA and try to double up, then take the add-on, but usually I'm sitting a little over 5.25K starting stack after the break, which is slightly below average.
If we look the player pool, 2047 players join the MTT and only 492 remain. So, more than 75% of the field is gone by the add-on. Out of the remaining 492, only 125 took the add-on. So there are a lot of players who are very short stacked and will bust out soon.
With payouts paying the top 50 players with < 500 players to go, and over 50% very short stacked, I think my chances of cashing or better are pretty good. I have a healthy stack and just need a few double ups to get there.
This 'strategy' works fine for me because I don't mind playing a shortish stack, late stage game in MTTs. If you prefer to play from the start, that works to. Just an idea.