I do not see the problem of adding the button of Zeno to being part of their equipment, you say that Goku is not in the same position as inventors like Phineas/Ferb, Jimmy Neutron, Dexter, etc. who heavily depend on inventions or tech to do anything outside their normal human stats.. but if that were the case because Future Trunks has access to his sword if he can perform feats superior to those of a normal human, it is not the same to compare a sword with the Zeno button, well another example, Vilgax has Chronosapien Time Bomb (multiversal weapon) despite being a character with statistics higher than normal humans. we just have to put a note that says it is not applicable to combat.