Yes. The following works, I’ve tested it on two of my own Red dimmers.
First update the switches to the latest firmware (1.48 as of this posting). On ONE of the switches (NOT both), set Parameter 12 to 11. Then once that’s done (and not before), un-associate with Group 2, and associate the switches to each other with Group 3 and Group 4. Finally make sure Parameter 1-4 is set exactly the same on both switches.
The association groups send different data. Group 2 sends a BASIC_SET command- the Z-wave dumb ‘turn on’ or ‘turn off’ that will work on almost anything. Group 3 sends SWITCH_MULTILEVEL_SET, which tells the switch what actual level to set to (0-99). Group 4 sends SWITCH_MULTILEVEL_START/STOP_LEVEL_CHANGE, which allows ‘live’ dimming.
Everything Group 2 does (on/off), Group 3 does better. A Group 2 assocation will carry on and off commands over, but a Group 3 association will keep the two switches actually synced up including dimmer level.
BUT the really important one is Parameter 12. P12 controls association behavior- what data is forwarded to associated switches. By default it sends everything, including data it gets from other associated switches. This creates a loop- you do something on one switch, it gets sent to the second switch, which sends it to the first switch, which sends it to the second switch, etc etc etc. Setting P12 to 11 on one of the switches breaks that loop.
Parameter 1-4 control dimming speed and ramp rate. I say make those the same so when you hold-to-dim on one switch, they both react at the same rate and stay in sync. If they don’t, the Group 3 association will fix it after you release, but it’s nicer to keep them in sync to begin with.