Yeah, things get a little 'interesting' electronics-wise  As sidehack mentioned, the connector isn't even remotely rated for that.

I've got a whole sheet of frequencies and hex values, but most of them are unlikely combinations of the various multipliers/dividers and some overlap; e.g. 200MHz fits 00111110000011 (0f83) and 00011110000010 (0782).  The latter is what is specced in the chip's datasheet - the series difference between them being the output divider value.  There's values well over 500 but I haven't even remotely approached 500 as it fails to initialize long before then  Looking forward to the new drivers - might poke at bfgminer as well, glad there'll be support in both