I have not done but the problems are well documented. Engine management is quite complicated and the manufacturers stay on the conservative side. A bespoke ad hoc solution from a tuner comes with a lot of unknowns.
They may follow a less conservative approach to management and skip the safe back stops, or they can go wild and falsify the input data in order to make the engine perform more. In both cases, sooner or later you will encounter problems.
In the first case, the management will not be able to react in well defined procedures and in the second case, you add too much stress to the engine for the gains you get back. Moreover, as you keep driving flat out, the wear will accelerate faster than driving an OEM car.
On top of that, you add extra stress to each component, from engine and gearbox mounts and suspension components, to the clutch, gearbox, EGR and DPF.
The biggest problem with the remaps is that by investing in upgrading the suspension components, brakes and tyres, you end up going faster while you are 100% legal.