I'm going to buy STF, as it seems it has all the elements missing from STRPG: a storyline and a clear long-term goal. I'm still going to play ST RPG though for some time. Reasons are:
1. ST RPG can be a great, single hand, vertical (!) phone game, while STF is clearly a tablet game for me. 2. ST RPG has the charm of many idle games, but without evil IAP 3. It's still so complex and rich and through great narration / copy it feels like a living, breathing, changing world. It's an absolutely fantastic feat, given how minimalistic the game is (graphically).
There's really little separating ST RPG from being a phone game for a long time for me.
A central "campaign", that can be ignored for a time, but completed when triggered (similar to Daggerfall). It can be something simple, a set of special contracts, but with varying ends that would lead to something bigger (like creating a new house / syndicate in the end, or own a star system, find some super ancient artifact, discover a mystery - whatever that would conclude your journey as a hero. Example - an invisibility artifact will forever cement your career as a pirate. Or alien-based super drug will make you into a legendary crime lord forever et.). Naturally - it should be very difficult.