Yes, the slow queries stay but there are some differences:

Same result set where other clients can crash, this scrolls smoothly so you can naturally load a bigger result set in the app than other clients would allow you to, It paints the UI considerably faster than DBeaver on my benchmarks, thats after the query has run. Memory footprint for the same result is considerably lower.

Basically, your db client can slow you down even after you have waited for queries so this will fix that.