Have to be honest I'm a bit confused about the desire to release a possible couple of more mph from a short wheel base brick thats best work is probably between 60 and 120 mph and is probably getting near it's realistic(for wheel base) terminal velocity at 143? Even more so in the UK to be fair even when tracking regularly there can't be many times you are running out of top end? No expert but that's my take on it all but I guess looking at the money some people throw at their cars it's an obsession more than a requirement! ?

It will certainly be interesting to see what speed increase is achieved once the limiter is disabled.
Looking at the rate of acceleration the limited car is achieving on the autobahn in sixth gear at the point that the limiter cuts in, IMHO the increase could be significant.
Of course, there is no highly similar car to base guesses on but as a rough example the BMW 128ti achieves 155 MPH.
It has similar power, wheelbase and is heavier. Not sure of its drag coefficient.
Agree completely that for many, the Yaris is primarily a very capable B road blaster and that is the use that lots of us will put it to. Me included.
But, depending on where you live, the capability to call on 150 MPH plus performance in certain motorway situations on the way to or from the B roads would be very useful on occasion.
If this could be achieved it would be yet another great feature of the Yaris. Especially for owners who have been used to driving high speed capable cars but wish to own a Yaris as their only car now.
As always, each to their own. Track it, hammer it through B road corners, attack gravel tracks or sprint down a motorway section from time to time. The Yaris is a multifaceted car which is attracting all kinds of drivers.
Personally I will be watching with great interest how the first users of the speed limiter defeat get on, but do understand if that's not relevant for everyone's use case.
There are a few intriguing possibilities as to why Toyota chose 230 KPH. Those in themselves might be of interest to all of us.
Everything from aerodynamic instability or drivetrain longevity to preservation of GR Supra sales ?