highly lossy materials in CST MWS

Hello all,
why is it that CST MWS cannot simulate materials that have tand>1?I cannot think of any explaination, do you have any suggestions?Is this a kind of limitation common to EM solvers?
If the tand is not much more than unity, then I use 0.99 as the value. But in the case of ferrites, the tand is around 30 (!). Any way round this problem?Or is it just impossible?
Thanks for reading
noob

let me give a brief reply. Good conductor is difficult to simulate with FDTD type solver because 1.you need extremely small mesh inside the conductor if you apply the same updating formula as in a lossless dielectric and low-loss material. To understand this, you just need to compute the wavelength inside the conductor using the complex epsilon; 2. a good conductor is very dispersive than low-loss material. again you only need to examine the propagation constant as function of frequency to see this. Consequently, it is difficult to obtain a wide-band source because the mode at the port is likewise very dispersive.
Frequency domain solvers are better in handling loss in good conductor. but you also need fine mesh to get accurate answer.