When ditching, I've found most planes to shake violently as they come to a stop and they continue to do so until I exit to the tower.
I've tested most of the planes on the roster by using no ordinance and 25% fuel, taking off with the plane, putting my gear up, and immediately belly-landing.
No Wobbling A6M2
the BF 110's
F4F
the P-47's
P-51D
the Spitfires
Some Wobblingthe F4U's
the 109's
205 and 202
the 190's
IL2
LA-7
P-51b
Ta-152
Typhoon
the Yaks
Violent Wobbling(These planes shake so violently that they soon explode)
the hurri's
Ki-61
La-5
Mosquito
N1K2
P-38
P-40's
I didn't test most of the bombers (they probably have the same problem), but I did try to test most of them twice to make sure that they shook each time). I finally broke down and tested most of them because I didn't like playing the lottery when I ditched.

I don't know if this's being looked into, but I've seen the problem since beta 1, and it would be a major bug to let slip into the full release.