I preferred ER Starscream to SS '86 Starscream, but still bought the latter for the throne and coronation gear.
I had this extra Starscream though, and wasn't sure what to do with it. Eventually I got Gen Selects Sandstorm, and thought it would be cool to have a Conehead Seeker body type with a standard Seeker head. SS '86 Starscream's helmet was painted a dark grey with a slight brownish tint, which I thought worked well with Sandstorm's desert camo scheme.
I thought it looked good and was ready for that to be that... except the standard Seeker head doesn't fit in the Conehead nosecone.
So a proper Nacelle- Thrust's body with the standard Seeker head- isn't going to be possible unless they switch the entire nosecone assembly out, which may not be possible with how the mould works.
It also means that a quick and easy G2 Ramjet to Slipstream isn't so quick and easy, because any female Seeker head would need to fit in that smaller nosecone cavity.
It's just really unfortunate there's not more universality there. Between fans mixing and matching and Hasbro potentially free to mix and match on their end... a standardized nosecone cavity would have made all the difference.