Not charging at idle.

LivewireBlanco said
About 1100 rpm is when it gets up to 14 volts using an aftermarket volt gauge installed. It's never died on me but it's gotten to about 11.9 before at night with lights on. I guess I'll keep an eye on it. If not I'll swap out the alternator since it's a lifetime warranty. It's a square back model.

Here's the part that makes it hard to judge. We don't know whether the battery is charging or not.* If this right after starting, it certainly is charging and that could be sucking a bunch of power. Once the battery is fully charged, then the only thing drawing power is ignition and field.

Chrysler expected a '37 Amp' roundback to supply a minimum of 23 amps at 15 Volts at 1250 rpm.
At 1100 rpm a '60 amp' square back should easily supply the 5 amps at 14 Volts needed for igntion and field.

Get the battery charged and measure the voltage at the alternator output and you'll have a better sense of whether the alternator fully working.
Here's a photo sequence showing the current demand of a battery needing recharge.
You can see a battery's state of charge is a big variable.

*assuming no ammeter.