You didn't state the total capacity for the softener nor the Control Valve brand or model.
If the softener contains 1 ft3 of resin, then the Total Resin Capacity will be 32K, but a 32K Capacity setting will provide the worst efficiency as 20 lbs salt would be needed each Regen cycle. (maximum efficiency: 32,000 / 20 = 1,600 gr / lb).
Assuming your softener is equipped with a 0.5 GPM BLFC (brine line flow control) flow restrictor, then the 6-minute current Brine Fill setting will refill the brine tank with 3-gallons water, which will dissolve only 9 lbs salt.
If the softener contains 1.5 ft3 resin (48K grs Total), then a 31.5K Capacity setting will require only 9 lbs salt, thereby increasing the maximum efficiency to 3,500 gr / lb.
When a softener is installed, the resin should be rinsed for an extended time before being sanitized with a small amount of unscented chlorine bleach added to the brine in the brine tank directly before being regenerated for the 1st time before supplying soft water to the home's fixtures.
The recommended softener startup procedure is described within the short writeup at the following link:
Softener Startup Procedure
You said: "Brine draw = 60 minutes, seems long since brine tank only has 3 gallons of water."
The appropriate amount of brine will be transferred from the brine tank within the 1st ~15-minutes of the 60-minute Brine Draw cycle. Once there is little brine remaining in the brine tank, the air check valve at the bottom of the brine tank will close to prevent air from being drawn in during the remaining ~45 minutes of Slow Rinse flow. The Slow Rinse will continue to push the brine downward through the resin bed, while also rinsing away calcium, magnesium and iron released from the resin beads, and will also rinse away chloride and excess sodium resulting from the brine that was just utilized.