At the shallow tables implied odds tend to be non existent, calling 3bets to setmine or with suited connectors is usually a big mistake at 50BB.

4bet would be all in for sure. If we make it 3BB, they 3bet to 12BB and we 4bet to 21BB, then if they shove we get close to correct odds to call usually, which isn't great as we commit ourselves when way behind.