Haste and Hindered Feedback with Mathematical Support
I do NOT gel with this change, and this will severely impact my enjoyment of the game. I understand WHY you're doing this, but I don't think this is a good change in the long run, and i'll explain why below. The first two paragraphs are a lot of math, so bear with me, but my first point is: Killer Haste/Survivor Hinder is fundamentally worse than Survivor Haste/Killer Hinder:
Lets say that a 4.0m/s survivor and 4.6m/s killer are 20m away from eachother. With no other variables, it takes (Distance [20m] divided by the speed difference [0.6] = chase time [33.3s~]) to catch up, or (20m/0.6 = 33.3~ seconds) in this case. It takes around 30s to catch up from raw speed differential for a 4.6 killer to catch up to a 4.0 survivor.
If either the survivor is 4.2 or the killer is 4.4, this time increases to 50s (20/0.4 = 50), and 100s for a 4.2 killer/4.4 survivor (20/0.2 = 100).
For a 3.8/4.8 Survivor/killer respectively, this time is (20/0.8 = 25). 5.0 is 20s. (20/1.0 = 20), 5.2 is 16.6~ seconds (20/1.2 = 16.6666~), 5.4 is 14.2~ seconds (20/1.4 = 14.28571429), etc.
Fundamentally, with the laws of distance/time, Killer Haste/Hindered innately has diminishing returns on chase time for Killers while Survivor Haste/Hindered buys you an insane amount of time against more standard killers.
With these numbers, a 5.0 killer only saves 10 seconds over a 4.6 Killer, (33.3s for 4.6 vs 20s for 5.0). Survivor Haste/Hindered is the complete opposite, granting you 50 seconds more for a 4.4/4.2 Killer/Survivor respectively.
(Side Note: This is partially why I vouched for 4.4 Scratched Mirror Myers when he was getting changes, since he takes 100 seconds longer to hit a survivor at 4.2m/s, and it becomes impossible to hit them if the survivor is 4.2m/s as well, since scratched mirror doesn't get bloodlust).
These numbers obviously don't count the benefit for map traversal, shortening/enlarging the distance between loops, or killer powers, but realistically this has two effects: Mobility/Killers with powers that don't care about a 0.2 or 0.4m/s increase (Nurse, Blight, Billy, Huntress, etc.), and are largely unaffected by Haste/Hindered perks that don't have extremely high values (Chem Trap and Champion at 50% actually does help a lot), while base movement speed Killers (Trapper, Myers, Freddy, etc) have the most to gain/lose. Killer Haste/Hinder can help the lower strength Killers fare better when higher mobility Killers simply get that speed in the first place.
My second point is the following argument for the fun of the game:
When making a build, you have a spectrum that goes from 'Tall' to 'Wide'. Building 'Wide' means building your loadout to cover as many situations as possible (ex: Pop/BBQ/No Way Out/Batteries Included), which is likely what most players end up doing. Building 'Tall' is the opposite, stacking as much as you can in one aspect, which is almost always objectively worse than simply building 'Wide' (Ex: Rapid Brutality/Batteries Included/Machine Learning/Game Afoot). There is one exception to this in DBD, and that's stacking four game-delay perks (Pain Res, Pop, Grim Embrace, Ruin), which is almost always the objectively correct build if you want to 4k, and are good enough at the game (or have a Killer with enough mobility/info) to take advantage of that insane amount of time provided.
Due to the aforementioned lack of impact on higher power Killers, building tall with Haste on mobility Killers is fundamentally way weaker than stacking Haste on Killers without mobility (or completely useless for Killers like nurse).
My third point is that these changes don't affect new player understanding in a relevant way:
This change does nothing to aid the understanding of new players, despite what the blogpost stated, due to the sole fact that there's still no visual indication that a killer or survivor has a haste effect, or a killer/survivor has a hindered effect. That's realistically the only change that benefits a new player's understanding of the game, as how do they know what perks you have if you don't have any visual indication except judging their speed by how fast they catch up?
Why not add a VFX 'woosh' that plays when a Killer/Survivor gains a haste effect, and the blighted syringe speed-lines vfx? As for Hindered, invert the 'woosh' so it looks like a debuff, and give Hindered blight's old C33 VFX when it still Hindered survivors, where they like drip n stuff. That'd go miles to improve the experience of new players rather than keeping them guessing about fixed values rather than variable values, which still keeps them guessing.
Plus, why not just teach new players how these things work? Give them tutorials, or like, proper tips/visual indicators. New players will only be 'new' players until they become good at the game, or learn about the game, which naturally happens over time. If we give them the tools to recognize and associate (the visual effects to indicate haste becoming active/being active) mechanics, they're going to understand why their chases are shorter, and adapt faster.
As for how I would change them:
We should probably treat Killer Haste and Survivor Haste like they're two different mechanics. Survivor haste needs to be more limited, regardless if it stacks or not. I'd say its the one haste effect I'd like to see limited in some form, since its benefit is insane compared to Killer Haste. Exhausted could prevent their haste perks, or they could be niche like Made for This, or specifically be unchecked/stack when its beneficial to stopping bad/unfun situations (Buckle Up giving a free sprintburst for slugged survivors, so that you discourage slugging).
Killer haste is fine the way it is IMO. I don't think like 10s off a chase is any different than sprint burst giving potentially 15-45s based on tile composition, and it only really benefits the killers with lower to no mobility.
I think Survivors being Hindered in the current system is also completely fine the way it is now. Killers being Hindered is a weirder case, since there's only two perks that do so right now (Champion of Light, and Chemical Trap), though they provide really nice utility against higher-mobility killers due to how big of a hindered value they are. I would suggest making it affect lower mobility killers less or equally, but higher mobility/movement speed killers more (maybe a total speed % decrease?).
Anyways, if you read this through, I appreciate it. I hope the math wasn't too hard to understand.