mm wavelength radar is known for short ranges, but those short ranges still add up to several kilometres in the Longbow radar and some others.
mmW is not very accurate at rangefinding, but capable of creating imagery without SAR tricks.
The addition of mmW radar to tanks for APS and as complementary sensor to IIR will likely drive up the costs even further - MBTs risk becoming too expensive.
It doesn't help to calculate that a tank with it will be so and so much more effective ceteris paribus. In the end, the rise in the costs of current tanks (even a plain IFV like Puma is at € 7 million drive away costs, 10+ if you add the periphery) may make them unaffordable in the necessary quantities.
A German army that goes down to 200 Leopard 3 for maybe six brigades would badly lack in MBT power compared to the cost equivalent of 2,000 T-90s, for example.