In the getFeePayer function, there is a comment on each of the switch statements similar to:

	case *clienttypes.MsgCreateClient:
		// Without this particular special case, there is a panic in ibc-go
		// due to the sdk config singleton expecting one bech32 prefix but seeing another.
		return firstMsg.Signer

Since getFeePayer is only called by Providers, the bech32 prefix should be passed in, and the address computed from the known prefix instead of calling .GetSigners()[0].String(), avoiding this data race altogether.