The Soulbinds endpoint should indicate which conduits are enhanced/empowered.
Here is the current output for a character that has this slot enhanced (Night Fae, Dreamweaver, renown 62)
{
"conduit_socket":{
"type":{
"type":"ENDURANCE",
"name":"Endurance Conduit Slot"
},
"socket":{
"conduit":{
"key":{
"href":"https://us.api.blizzard.com/data/wow/covenant/conduit/157?namespace=static-9.1.0_39069-us"
},
"name":"Marksman's Advantage",
"id":157
},
"rank":8
}
},
"tier":1,
"display_order":0
},
Adding a flag alongside tier would provide enough information for clients to properly display/handle this:
{
"conduit_socket":{
"type":{
"type":"ENDURANCE",
"name":"Endurance Conduit Slot"
},
"socket":{
"conduit":{
"key":{
"href":"https://us.api.blizzard.com/data/wow/covenant/conduit/157?namespace=static-9.1.0_39069-us"
},
"name":"Marksman's Advantage",
"id":157
},
"rank":8
}
},
"tier":1,
"display_order":0,
"enhanced":true
},