Can this Homekit item be set in the UI? or only Textual

I want to not be required to have any text *.items files
This seems to require a text file.

Dimmer GarageLight_0022A30000361236_1_Dimmer "Garage Light"  {homekit="Lighting" [dimmerMode="filterOn"]}

Can this be represented in the UI admin?

OH3 3.2 snapshot

you can add config details via UI → Code tab.
i dont have dimmerMode, but here is another example.
Duration is homekit tag i.e. in your case “Lightnng”.
homekitDefaultDuration is the configration parameter, i.e. in your case dimmerMode

I’m setting up my item metadata like this

value: Lighting,Lighting.Brightness
config:
  homekitdimmerMode: filterOn

This is my log turning off then on from homekit

2021-11-11 19:49:30.850 [INFO ] [openhab.event.ItemCommandEvent      ] - Item 'OfficeLight_0022A30000361157_1_Dimmer' received command OFF
2021-11-11 19:49:30.851 [INFO ] [penhab.event.ItemStatePredictedEvent] - Item 'OfficeLight_0022A30000361157_1_Dimmer' predicted to become OFF
2021-11-11 19:49:30.858 [INFO ] [openhab.event.ItemStateChangedEvent ] - Item 'OfficeLight_0022A30000361157_1_Dimmer' changed from 100 to 0
2021-11-11 19:49:35.016 [INFO ] [openhab.event.ItemCommandEvent      ] - Item 'OfficeLight_0022A30000361157_1_Dimmer' received command ON
2021-11-11 19:49:35.018 [INFO ] [openhab.event.ItemCommandEvent      ] - Item 'OfficeLight_0022A30000361157_1_Dimmer' received command 100
2021-11-11 19:49:35.020 [INFO ] [penhab.event.ItemStatePredictedEvent] - Item 'OfficeLight_0022A30000361157_1_Dimmer' predicted to become ON
2021-11-11 19:49:35.023 [INFO ] [penhab.event.ItemStatePredictedEvent] - Item 'OfficeLight_0022A30000361157_1_Dimmer' predicted to become 100
2021-11-11 19:49:35.024 [INFO ] [openhab.event.ItemStateChangedEvent ] - Item 'OfficeLight_0022A30000361157_1_Dimmer' changed from 0 to 100
2021-11-11 19:49:35.132 [INFO ] [openhab.event.ItemStateChangedEvent ] - Item 'OfficeLight_0022A30000361157_1_Dimmer' changed from 100 to 0
2021-11-11 19:49:37.101 [INFO ] [openhab.event.ItemStateChangedEvent ] - Item 'OfficeLight_0022A30000361157_1_Dimmer' changed from 0 to 56
2021-11-11 19:49:37.115 [INFO ] [openhab.event.ItemStateChangedEvent ] - Item 'OfficeLight_0022A30000361157_1_Dimmer' changed from 56 to 100

It does not appear that the ON command is being filtered. Any obvious problem with my HomeKit metadata?

What’s up with 4 state changed events?

See “Jitter” (looks like a ramping dimmer in action here)

The dimmer is a Leviton DG6HD
I would guess it is a “ramping dimmer”.
Press the ON/OFF rocker and the light fades on or off
I’ll try disabling autoudate