Killer velocity should effect their terror radius/warning they give. to an extent.
Killers moving at high speed : think billy with double engravings, spirit with double speed/mother daughter ring, Nurse with distance addons, The oni with speed addons etc etc, all have one incredible bonus that no one talks about. they give less warning whilst coming across the map. Infact one of the best perks you can run on these killers is monitor and abuse (excluding spirit for reasons) as it gives less warning as you approach/allows your speed to have an even greater effect. Whilst stealth is great and fun on hyper agressive killers such as these, Having at the very least opportunity to react to something puts alot more information into the hands of players allowing for a higher objective feel of balance.
now i play a lot of oni, and a decent amount of spirit/nurse. The amount of times i've arrived on top of a survivor without them realizing im already there is nuts, despite my start of power roar and charge noises. and its happened to me as survivor too. i don't think their terror radius needs to be raised in radius, but there are certain things that could be done that could make these killers give a far greater illusion of balance. The best perk i feel i can run on oni infact, is actually tinkerer. i pop my power when i know a gens close/when i get the notification, speed on over at the speed of light and scare the hell out of survivors.
by for example! : tweaking the warning sounds they give - oni's roar at the start of his charge being directional, so you can tell if he's coming in your direction or away from your direction. same with nurse. have her blinks be a bit more indiscernable if their moving away/going elsewhere, whilst if shes coming towards you act as normal. Hillbillys chainsaw could be simply made louder with the sound addons making it far quieter up until near or actually silent (as in doing so your sacraficing other good addons on him.) Speed addons on spirit could increase the warning distance she gives, expecially the mother daughter ring, allowing players to react better to playing against them. Simple things that if one is paying strict attention to, might give away the killers direction, but not their speed or location.
The reverse goes for slower killers. Hag has a slower movement speed at default and she actually gets a smaller terror radius! brilliant. same goes for deathslinger despite his range, with it playing into his kit even with entire builds based around it. Huntress is the edge case where her warning lullaby needs to be loud, but that was made non-directional which is also a brilliant change, giving warning without making her entirely stealthy. Micheal has his breathing in tier 1. ghostface has his shuffles you can hear if your observant. Hell freddy even though he's default speed, gives ample warning with his gen teleports whilst they still remain strong as he can fake them out!
Giving sound based warnings direction for high velocity agressive killers would also play into their skill cap a bit. Fake the oni's roar in a direction, and curve towards players. As spirit if you know their going to be warned a lil earlier by using speed addons on your power, approach from a different angle where you might expect them to be etc etc.
Comments
They could change it so those speed add-ons have a drawback instead.
"Your terror radius is increased by x" or "Your chainsaw is louder"