Two Blue's in a 3 way (non-smart bulb)

I’ve got a traditional 3 way Line/Load in same box (neutral wire setup) for a fixture with non-smart bulbs that I want to use Blues on both ends and with dimming capabilities.

I’m using the wiring instructions from this guide Resources | Wiring Schematics - Wiki & How-To's - Inovelli Community, specifically as described in this image: https://community.inovelli.com/uploads/default/original/2X/d/ddb10e562f3c7fc8b0967714a712aa0fec6f453f.png

What should the switch parameters be on the primary switch to function as a dimmer? (I understand the second “aux” will require a zigbee specific config; I should be able to figure that out once the primary is working as expected.)

(using zb2mqtt and ha, not that that should matter for this issue)

Thanks,
Bryan

Parameter 258 - Switch Mode (Dimmer or On/Off)
Determines the mode of the switch (On/Off or Dimmer)
0 = On/Off
1 = Dimmer

Seeing as the Traveler is not used, should the switch be in Multi or Single Pole?

Leave it at single pole since you are going to either bind or use scenes.