The reason for the trip is just a gimmick to get the ship to a specific location ie hex 0808 in Villis subsector. I want the story to be true to Traveller and easy enough for someone who wants to just enjoy a good storyline without being a "mental contortionist" to follow.
There are things the Author needs to know, so as to keep the story internally consistent ... and there are things the Reader needs to know so they can follow the story and have events make sense. It's alright to have details "in the background" that the Author declines to reveal, but which can be inferred from how events play out during the course of the story.
If your intent is to have some "precipitating event" at Vilis hex 0808 (deep space between Ficant and Lanth on the subsector border), from a story perspective, that's an easy one.
The ship is J3 capable.
The ship makes a J3 transit from Frenzie to Ficant.
The ship makes an ocean refueling stop (no gas giant), maneuvers away to a jump point ... tries to initiate J3 ... and the drive aborts and shuts down (safely) without initiating jump.
Cue engineering scramble to figure out what went wrong.
Crew determines that their jump drive alignment has been degraded (somehow, detailed explanation not required) such that the ship is only capable of J2, not J3 until they can get shipyard repairs ... which they can do at Lanth (where they're going).
The jump abort used a lot of fuel, so the ship wilderness refuels at the Ficant ocean again (just to be safe), maneuvers away to a new jump point ... and successfully initiates J2 to deep space with sufficient fuel onboard (ship is J3 capable) for a followup J1 to get to Lanth from deep space.
That then puts your ship and crew in Vilis hex 0808 like you were trying to get to.
Such a formulation also has the benefit of throwing "a little bad luck" at the crew before getting there, such that what should have been a ~2 week job is now turning into more of a 3-4 week job, with all the extra downtime at Ficant and the engineering crew being "on edge" needing to babysit the jump drive until reaching their final destination (because if it goes down completely, everyone onboard is dead). Best case scenario would be a misjump to an inhabited system where they could be rescued, but that would be a pretty dire outcome. Point being that once there's the mishap at Ficant you've got your crew biting nails and hoping they can make it to Lanth.
I like your spend on the Megacorp, but it comes across as something for seasoned Traveller players rather than a casual reader of science fiction.
I wrote that from a "the Author needs to know what's happening in the background" perspective, rather than it being something that the Reader (let alone the ship's crew) needs to know about or be told explicitly. Even if that level of detail doesn't appear within the story itself (explicitly), if the story is written well a knowing Reader who
reads between the lines could figure out more (simply by knowing Traveller as a setting) and have an added layer of appreciation for what you're doing in your story. That way, the megacorp backstory details are essentially kept "behind the curtain" but the Author needs to know those details in order to make events line up properly in a coherent way for the rest of the story to unfold within.
It's kind of like shadow puppets in that regard. You need to know how to position your hands in relation to the light so as to be able to make the shadows on the wall present the images that you're intending to make.
Suppose I do something like Al Mora has an agent and some cargo that he or she needs to get to Lanth ASAP, for unspecified reasons
In the context of the story, unspecified reasons are the best option ... largely because it then leads to the inevitable speculation (both by the Readers and by the crew within the story) as to what those reasons might be. A lack of certainty/omniscience is definitely an Author's friend on this point.
It's okay for the Author to know why ... but you're under no obligation to share that with either the ship's crew or the Readers. Just like with an adventure, sometimes there is more fun to be had from the guessing game than there is from having the answer handed to you on a silver platter.
they currently do not have any means avaliable at Frenzie at the present time other than the regularly scheduled route service ships.
Which will "take too long" for a time sensitive/perishable delivery of {fill in the blank}.
"Yeah, we can ship your fresh fruit for you. We can have that delivered in 8 weeks. [...] What do you mean that's not good enough for you?"
Basically, the ship used in this case would be an "alternative route" that needs to be hired on a "hurry up" basis. Could even do it as an interstellar charter if you wanted to "book the whole ship" for this particular job. The contract could even be for 2 jumps worth of charter booking (J3+J3) from Frenzie to Lanth ... which winds up not being exactly what happens, but that would be the setup at Frenzie for the booking.
The subsidized merchant liner and her crew have earned a trustworthy reputation within the Villis mercantile community and happen to be in port to receive the offer.
Does that seem to fit the bill?
It's certainly sufficient to kick off many an adventure in Traveller.