Perk tier rework/rebalance idea
This is a quick copy paste from me on why CoH wasnt addressed in the PTB. I personally do like the idea of 3 perk tiers, but the bloodweb alone makes everyone wish it was just 1 tier. Considering BHVR also likes the aspects of 3 tiers and probably wishes to future proof the grind, I think this would be a solution to both sides of that coin.
Ofcourse this wouldnt directly apply to all perks equally and some perks would need bigger changes than others, but it would somewhat help with mapsize.
Basically, you just equip the perk, and the mapsize dictates it's effect.

Comments
I made a similar suggestion a little while back where I recommended that area effects centered on a point or character have ranges that are proportional to the map size. So rather than a flat 32 meter range it's something 32% of the maximum width of the map (assuming an average map is 100m wide as a placeholder here). This would apply not just to area effect perks but also the killer's terror radius (since there are a lot of effects that happen within the terror radius).
Obviously devil is in the details, but I agree that in principle making area effect radiuses vary by map size could help with some of the balance variances on these sorts of perks.
Well, the Terror Radius is more an indication of the time it takes for the killer to close the gap if you were running in a straight line. The time for a 110% killer to close a 24 meter gap is quite close to a 115% killer closing a 32 meter gap. It's often the weaker killers that avert from this standard because they rely somewhat on stealth.
But while there are obviously perk effects that would effectively the same on all maps(take Monstrous Shrine for example), you can somewhat rebalance them by having different effects on different sizes. Monstrous Shrine could easily be much, much harder to unhook yourself on big maps, but slightly slower sacrificial speed, effectively forcing the basement survivors to be rescued by teammates(which is quite a big survivor timesink and discouraging camping), while the sacrificial speed could be faster on smaller maps(if the killer is away from the basement), forcing survivors to leave gens much quicker to go for the rescue, making the time between chases much easier.
Area of effect doesnt always need to be based on size depending on maps.(Surge is quite fine in terms of size, for example), but their effects can be made stronger on bigger maps.