I wouldn't worry so much about SPR at 2nl, and focus more on range and pot odds. Your SPR doesn't tell you you must call when it's a set figure. It is better as a guide as to how much to bet at any given time, assuming we're trying to get all the chips in over the course of the hand. It serves as a tool for hand planning, not as a marker for being "pot committed". It's probably more important in tournament games, rather than cash games, since we should always have at least 100bb in cash games and therefore maintain a high SPR. It can be applied in hand planning for cash games, but really it's beyond the realm of the vast majority of 2nl players.

Pot odds and equity are what determine if you're pot committed or not. This is much more important at 2nl.

Keith, of course this guy can r/c small pairs from this position. It's 2nl and he looks like a fish to me. Your range is too strong, you're talking yourself into folding a clear call imo. If he plays a set like this, chances are he drools with top pair and any flush draw he calls pre. Unless I've got some decent reads by now, I'm assuming he has all Axhh, some junk hh, AJ, some KJ, some other suited JQ/JT/J9, and sets. Less likely JJ than 99/33 since someone who is this aggro on the flop is more likely to overplay JJ pre flop. This is a clear call for me. If he has a set, nh reload etc.