I'd personally err on the side of too long. I reused spokes (>30 year old French spokes, btw) when converting from a geared hub to a singlespeed flip-flop. The former nondrive side spokes were long enough that I ground them down even with the inner faces of the nipples and have never had a problem with them.
I worry that going a mm or so shorter than called for means about a thread and a half less engagement in the nipples. In other words, I'd go with all 296, rather than 295, but I don't think it will matter in the long run. Of course, if you use 295 and the spokes are tight after just a turn or so, you may want to consider spending the money on longer spokes before you end up needing a new rim and all after they fail catastrophically.