While you can’t abort temperature_waits in mainline Klipper, if anyone’s interested, I was able to implement this in my fork of Klipper (also I merged PR #6662 into my fork).
- Instant cancellation via webhooks (cancel button in Mainsail/Fluidd) feat: Instant print cancellation by G-code API · Klipper3d/klipper@2260fe7 · GitHub
- Instant cancellation via G-code webhook (
CANCEL_PRINTcommand in Mainsail/Fluidd console) feat: Add instant print cancellation · Klipper3d/klipper@372bdf4 · GitHub
Essentially, when a cancel command is detected in the queue, it aborts all heating then runs the usual CANCEL_PRINT macro.