The problem with the broken effect add ons
Broken as a concept is neat, you prevent survivors from healing for a limited amount of time. The problem is, with as many options for placing the mangled effect on survivors that killers have, the effect functionally becomes a secondary option for anti-healing. Negating healing for a short amount of time isn't nearly as valuable as making their healing slower. Why? Because of time. The longer survivors spend in the match the less resources they have available (pallets, players, extra gens to work on- etc.). At first this would make it sound like broken like an amazing thing to have, but all it does is prevent healing. They can still do gens, cleanse totems, and help other survivors instead of healing. Mangled? they get to heal alright, just WAY slower. This means not only are they not healed as quickly, the main benefit of making them broken, but they also do so in a way that forces them to choose either A: heal now and spend time not doing gens/totems etc. or B: ignore the injured state at risk to yourself to get other things done, while also not getting any healing done meaning you'll eventually have to spend that time healing yourself anyway (this is excluding mangled effects on add ons that go away after a certain amount of time, but those are basically just worse versions of the broken add ons, which considering I'm making a post about why broken effects aren't that good should tell you exactly how useless the timed mangled addons can feel). The overall result? Mangled stalls the game far better than broken simply because of the lose-lose situation it puts survivors in, while also being far easier to come across with how many mangled perks and add ons there are.
Solutions: luckily there are some pretty simple ideas that can make broken far more worth taking as an addon.
1- more time. This is easy to implement but most likely hard to get right. Making the broken effect last much longer than the mangled effect would make this less of an inferior version and more of a side grade. While not as effective at preventing survivors from doing other things like mangled, it does excel at making them actually STAY INJURED for far longer thanks to them not being able to heal at all. I would recommend the amount of time being a good bit more than how long it would take to heal yourself under the effect of mangled. They are still getting things done, but now they are at risk while they do so (unless they decide to wait out the duration by hiding, which means they get nothing done and still somewhat at risk).
2- conditional removal. Instead of having a set time limit, you could force survivors to take certain actions in order to remove this effect. This would make it a good distraction from normal play, by forcing them to go out of their way to do something to make themselves able to heal again. Admittedly this idea works for some killer powers better than others- as I imagine it forcing survivors either to 'cleanse' themselves in some way (such as using EMPs from singularity and other such inbuilt 'counters' that some killer powers have) or to do a normal action like enter a locker for a set amount of time.
3- extra effects. This one is more of a shotgun of ideas. Adding additional effects and making the broken status a 'side effect' or at least another thing to worry about would make these perks more worth taking to distract and disorient survivors.
4- Change broken effect. This one is probably a more controversial idea, but I think it has merit: make survivors heal slower in the dying state instead of injured. It's essentially a weaker version of the knock out perk, without slowing survivor crawling speed, in order to allow killer some more room to breathe when they down a survivor. Sometimes there's too many to deal with at once, or perhaps there's a pesky flashlight user trying to force you in a no win situation, this would help with those circumstances. It also would help broken have it's own identity outside of being 'mangled but different', which is good for the game I would think.