There's a slight benefit to be had by going into ground effect. If you time it exactly right, you could probably clear an obstacle marginally farther away by timing your entry into ground effect before the obstacle and then pulling up before crossing it.
The chance of getting it right would be next to nil though, IMO. The risk of ending up in the obstacle at a higher speed or stalling out on the pullup would be significant.
Going into GE to save the day is not an uncommon tale in glider pilot folklore.