Scala 3 Match types Channel subscription

Subscription.scala

case class TradeEvent()
case class OrderEvent()

type Channel = "trades" | "orders"

// def sub2[Channels <: Tuple](channels: Channels)(using Channel <:< Tuple.Union[Channels]) = channels.toList

type SelChannel[C <: Tuple] = C match {
  case "trades" *: xs => TradeEvent | SelChannel[xs]
  case "orders" *: xs => OrderEvent | SelChannel[xs]
  case _ => Nothing
}

def subscribe[Channels <: Tuple](channels: Channels)
  (using Channel <:< Tuple.Union[Channels]): List[SelChannel[Channels]] = 
  ???

val tradeSubscription: List[TradeEvent] = subscribe(Tuple1("trades"))
val orderSubscription: List[OrderEvent] = subscribe(Tuple1("orders"))
val allSubscription: List[TradeEvent | OrderEvent] = subscribe(("orders", "trades"))