Calling all Killer mains.... End Chase or Map Control?

Map Pressure is what wins all games. Having said that, the best form of map pressure is downs, which is a function of your ability to chase. So you're asking whether A or B is the best way to win when A is a subset of B. It'd be more appropriate to ask whether downing a singular survivor or injuring multiple survivors is a more effective form of Map Pressure.

Killers with good map pressure are definitely better than killers who are just good in a chase. No matter how fast you win a chase against a single person, you still have 3 other survivors out there potentially rushing generators during that chase. Obviously killers who are both good in a chase and have good map pressure, like Spirit and Freddy, are top tier though. Spirit is not only fast in a chase, but she can get around a map quickly to check gens and scare survivors off of a gen when they hear her phasing sound because they don't want to get pulled off the gen. Freddy is also great at both, his traps make several loops unusable which can end chases faster, while his gen teleporting and teleport fakeouts are great for map pressure.

Those are near synonymous so that's kind of a weird question to answer.

Part of how you get map pressure is through knowing when to end chases early.

The entire reason you want to know when to end chases is because you need to keep map pressure.