I appreciate the response. You're right. I thought of level 15 because players might return to the Ebon Hawk before reaching that level after they got their third lightsaber part. It mostly happens ( for me, at least ) before reaching that level. That leaves only the lens which could be acquired by fighting Visas, which justifies returning to the ship before finishing the first planet in general. This information might not be available to new players, so I get it if they don't return to the Ebon Hawk early (except if the red eclipse attack occurs on Nar Shaddaa). I agree level 15 is not enough to save this problem, and any additional level restriction might make players miss some of her interjections across planets.
An alternative is to keep Visas unconscious based on influence with the Handmaiden because the latter locks the player out of talking to her once the exile has 30 influence points more with Visas than her (Acoording to the stategywiki) which means as long as Handmaiden has 74 influence points or more, she won't hate the player ( most players in their first playthrough want to gain influence with their companions rather than trying to lose it, and it is likely they would have gained 16 influence with the Handmaiden by the time visas attacks the Ebon Hawk ). If the player decides to lose influence with the handmaiden ( mostly on their subsequent playthroughs), Visas should be unlocked when the handmaiden has less than 40 influence points. If she already has that number of points before Visas can join the party, no unconscious state would occur.
As for locking the player of access to Visas, the PC can try to heal some of her wounds depending on the treat injury skill, which would give a little boost to her life points or a bonus to her constitution. To make it clear to a new player, when he approaches visas a pop-up would say ' Visas needs to rest. She will recover in due time, but you can help heal some of her wounds' or something like that. If the exile failed, he would just wait for her to wake up normally. For a female exile, the same things could happen with the disciple, only for the sake of consistency, but keeping the vanilla behaviour would be good.
I hope I'm not bothering you, since you didn't like the idea in the first place.