Ship Talents and Traits

My group is doing well on missions, most are RPG veterans, and upgrade well, with the alternative experience system. they just done their second arc stone for each. My engineer in particular upgrade the ship with his.
And it doesn’t include traits, like tachyon detectors they paid during “entropy demise”, or “extensive connectivity” talent, they managed to keep once the Escalente system was uninstalled in “pleague of Arias” (have made the Escalente System a real time tele reality with cameras everywhere except toilets and sickbay, with cameras and mikes on head officers too, except medical officer and ship Councillor, for 2 threat points after one player said “hopefully we don’t have camera on us”, making the pleague of arias a federation scale threat), once the cameras and transmission removed the engineer kept the console improvement.
But the more scenarios they do the more they want to upgrade the ship with arc stones, to the point where I wonder do you put a up-limit to ship talent or traits?