Playing with the VTEC crossover isn't really that important for a turbo car unless you change the cams. Otherwise the majority of the tuning is done with a/f ratios, and in that area the SAFC is actually a bit more flexible than the VAFC.

For now if you install it, it's obviously not going to do anything until you tune it on a dyno. For when you get a turbo what you can do is run some higher flow rate injectors like RC 440s or DSM 450s and a better fuel pump, then set the AFC to -40% fuel trim across the board and it'll run pretty nice. Of course that's a preliminary setting and it will still run better after tuning.