Which I don't think that's possible. I can see 279 among IEE's and EIE's, but not ESI's.
The only option for me I guess an ESI 479.
Or just go with the IEE/EIE 279, but then that's not my dual. But anyway, I always like my benefactor and my look a like.
My point is, I like a 2 and 7 in someone's tritype, but dislike a 6 and 1 probably because I don't like Si.
So I think if my dual, ESI, doesn't have 6 in his tritype, that would be good enough.