I wouldn't remove it.
I don't know how it is in the UK, but in Europe the removal of DPF is a big topic now - because it is illegal and many people are solving this problem with removal.
The car inspection companies (like TUV in Germany) all over Europe are forced to buy new measurement devices, to detect missing DPF.
In Austria and Germany the police is sometimes measuring on the street. If they find out, you get a big fine and they remove you the number plates.
Try to solve it first. Let clean the Differential pressure measuring unit hoses - the unit is located to the left in the back of the engine compartment, over the DPF - with two black rubber hoses going to it. Then get new ECU software from Lexus - they've updated the code to reduce the smoke (they've updated it 2-3 years ago, so check if you have it already installed or not)
If your only problem is the smoke, do those two things - the smoke will be decreased (it will not disappear!), but this is still better then removing it and later have troubles - IMHO.