It is not very practical to provide both pickup phase selection and series/parallel selection in the same circuit. It is certainly possible -- but doing so requires either a large number of switches or very special switches which are not commonly available. I've experimented both with phase selection and with series/parallel selection and I find the latter far more useful -- but if we were all the same there would only be one type of guitar, one type of amplifier, and so on. So, I've included at least one modification that I've tried that features phasing.

With phase selection, you can choose two pickups wired such that they "fight" each other -- their signals are out of phase. The resulting tone is weak and thin and seems -- at least to my ears -- to emphasize the higher harmonics. The one exception to this is selecting the neck and bridge pickups out of phase when using hot pickups, the result is a sort of "hollow" tone that is interesting. I still have one Strat that I wired for phasing but I only use the neck/bridge combination out of phase, and that only since I installed humbuckers at neck and bridge.

I've found that the difference between series and parallel wiring for the pickups produces tones which are much more useful. But, that's me and what I like. If you are really curious about what out of phase pickups sound like, simply temporarily switch the two leads from the middle pickup. If you like the new tones at the "2" and "4" positions, then by all means consider the phasing modification.

In some cases phasing can be quite interesting if the pickups are also wired in series.  The T-Riffic™ modification provides a neck/bridge in series and out of phase position that is stunning on a standard Tele, for example.