How to send IOT Link MQTT message from PC

Tags: #<Tag:0x00007f325d660350>

I’m trying to send an MQTT message from my PC when it starts up and when it goes into standby/hibernate/shutdown etc…

I have figured out how to do this by the LWT message but It’s not an immediate status change - it takes a minute for this to change to ‘off’ and all of the other monitored entities to go offline.

How might I best achieve this and where would I put this in the IOT Link files?