I never push with small PPs in cash games; short-handed or otherwise.

Why? Two basic reasons.

(i) Even though you have a small edge over two un-paired over-cards, why risk your whole stack on such a small edge? I'd rather see a flop and try to hit a sneaky set and take my opponents' whole stack (in other words, implied odds will increase the EV of these cards played this way relative to a simple push as a 55:45 favourite).

(ii) You have a small edge pushing with small PPs only if you are correct that your opponent(s) are in fact sitting on un-paired over-cards. What if you are wrong? The times that you are wrong and you are in fact up against a higher pocket pair will definitely erode away at that 55:45 advantage. Making this play go from being slightly EV+ (assuming you can be correct 100% of the time), to EV -ve.