Since Kotlin threads appear to be Java threads (NB: Just following their documentation, I've never used Kotlin and have only started learning it because we may

Since Kotlin threads appear to be Java threads (NB: Just following their documentation, I've never used Kotlin and have only started learning it because we may use it at work for some things in the near-ish future), you oughtn't use Thread::suspend. It's been deprecated for a while. Java threads are preemptible, though. You don't need to explicitly suspend them (even if that method weren't deprecated) since the scheduler will happily do it for you.