It's not uncommon to do this and should be justifiable given the relative closeness to 5 April.
However, it is concerning that advice is being sought on a public forum around a £200k termination settlement. Paying a settlement of this magnitude without proper professional advice is just madness IMHO.
Just remember, you can say what you like in a compromise agreement but it matters not one jot from a tax point of view. It is the contractual terms that dictate the tax treatment of the various elements of the settlement.