This will most likely be very controversial, but...
I think the hulk gene should be removed (or at least disabled so it can't be acquired via number means, such as through genetics).
Hulk gene is so overpowered, it resists almost all forms of stuns, and it can be used to break through almost everything (walls, reinforced walls, anything that can be destroyed).
Not only that, if it's coupled with any other equipment (hard suits, science garbage meme chems, traitor/antag abilities) it ends up even MORE overpowered. Hulk gene is also notoriously also abused by non-antags at times.
Even though the hulk gene makes the user end up having with their DNA very unstable, it's still very strong.