Hi, Boys and Girls!
While in DH we have the option to integrate moderately gifted sanctioned "psykers", persons who have other priorities than just warp powers on their agenda, like the Adept or via ascension "Mind´s Eye opens", "Psyker´s Gift", in RT non of the "main" classes beside the Navigator/Astropath have that option.
It is doubtful that there is a Rogue Trader or other RT class in the whole Imperium who has no sanctioned members. In my group we handle chars who will be gifted, like the "Psyker´s gift" and reduce the PF a bit, since the Trader or other class will be away for some time until coming back sanctioned. It costs them massive amounts of XP to get some powers and Psy rating, so they get some minor powers and one, two discipline powers mostly. If they want more, their other char options suffer. All right for us. A RT with one or two Biomancy powers (good to keep healthy and looking impressive) or Telepathy (like knowing when lied to or a Voidsmaster gunnery officer with frightingly good aim) are not gamebreakers, if handled with care. And in-universe there must be some sanctioned psykers in the RT fleets, even leadership. It´s too big a universe, that not even one RT has success in part because of his psy powers.
What would you do/say about how to implement chars with some psy power in RT?