Jynx has plenty of potential already, fantastic, except for looks and has that awesome 115 SpA and Ice type STAB. It also has that fantastic ability to run 3 very good sets and 95 Base Speed is still very good. Electivire can't hurt a Caterpie, seriously. While Magmortar can, it is too slow. Jynx is a perfect balance of power and Speed. Which, if given an evo, will surely become at least BL material with a possible boosted Speed and that already big SpA.
EDIT: on to Frosslass...it can't hurt anything. I'm sure you would call 284 SpA medicore especially considering Jynx reaches 266 SpA with 0 EVs in SpA and a neutral nature. :D