Is cable capacitance of less consideration when used with a low-impedance MC into low-ish input loads (<1KOhms)?
Yes, it will tend to be less important in that situation than in most others. But it can still be significant because depending on the phono stage reducing the capacitance may allow sound quality to be further improved by increasing the value of the resistive load. For further explanation see the post by JCarr (Lyra cartridge designer) dated 8-14-2010 11:20am in
this thread.
BTW, I should add to my previous comments that there are a few situations in which minimizing cable capacitance will not be optimal. Those would involve certain moving magnet cartridges that are specified to work best when loaded with high amounts of capacitance, e.g. 400 to 500 pf, especially if the input capacitance of the phono stage (which is often unspecified) is low.
Regards,
-- Al