I posted both of the required tables in post 274 and 285. In all cases that I've checked the final segment climb gradient meets or exceeds the 2nd segment gradient. As mentioned before, the final segment gradient is with the engine at max cont rather than max thrust which is the case for 2nd segment. So where we are only able to match the 2nd segment climb (which would be good enough anyway) we will actually substantially exceed it because for the remainer of the time available we will remain at max thrust.
There is no acceleration (in the event of an engine failure at V2+20) - we are already at V2+20 so don't need any acceleration. All we need to do is keep that speed - while the flaps travel the gradient will change from the flapped to the clean gradient. We do not accelerate. We still have the 1500 foot level acceleration platform available to accelerate from V2+20 to Venr so that we can establish in the enroute climb when necessary.
That acceleration phase in the level segment will be shorter than in the calculate scenario where the engine failed at V1. So our obstacle clearance calculations are still valid.
In all cases we outperform the critical failure at V1 case. Thats without counting all the other factors which are actually in our favour.