I have done this mod, and really like getting a significant amount of current flow out of the bulkhead connector (and the ammeter). My meter reads "slightly discharged" from the middle marker while everything is working properly under minimal load, and this is the New Normal for that meter (and yes, is slightly annoying). Turn on blower or headlights and the meter shows an alarming amount of discharge, but this is simply the same amount of discharge movement that you would see from the middle marker if you hadn't made this mod. When the car is off, the meter settles back to the middle mark. Also, I used black 10 guage wire so everything looks OEM, and soldered the connections for permanent and perfect conductivity, including the fusible link. I'm not a big fan of large crimps.
I have also powered my AC clutch via a relay (tucked away and invisible under the receiver dryer, all wiring looks normal), powered from the alternator stud and triggered by the pressure switch wiring. This has taken another 5-6 amps out of the bulkhead connector AND doesn't show up on the ammeter, since it's all on the battery side of the electrics and not through the meter anymore.