I would be happy for that. Being able to prevent someone from fleeing for that long should be a calculated risk for the one who entwines.

If it really makes the opponent dodge worse than you, then entwine is too much I think. There should be a slight trade-off. Because the entwiner can also flee if it's going poorly (at least one fled from a char I had after he entwined me).

So, it should be no one can flee OR the entwiner is at a slight combat disadvantage.