I have the lcd51v model, I tried it out because there was a thread about the 51vm model posted by another user, stating he used it without a sd/ff.
It seems they both handle the native amiga 15khz.
But i can only verify the 51v myself.
Also, there is nothing listed in the manufacturers spec, at least that I saw, that stated it could handle the 15khz. But it does...
Another point: I did not try the monitor with interlaced workbench modes, so it may flicker.