the biggest reason for digital FM to be so stable and clear is tuning, because tiny differences in tuning make for big differences in sounds.
In the case of PM, as in the Yamaha Classics, there is no need to go thru zero,because the oscs base frequency will stay the same.
So to come back to the OP, you will not be able to create those sweet, sparkling bells with analog oscs generally and even less with the MxB for a number of reasons, nontheless tuned metal objects are certainly to be created and some of them even on the sweeter side.
Make sure the brute is warm, tuned (after warming up), and dial in the ratios very carefully, you could also use a macro knob with e.g. 50% mod intensity on the modulators freq or the FM index for more precision.
I did find the excellent article on FM, but sadly it is in German. If you happen to understand that, do check this out, its rad:
https://www.amazona.de/synthesizer-4-was-ist-fm-synthese-und-phasen-frequenzmodulation/Maybe we can determine, which type of FM it actually is, the MxB offers...