This is going to be difficult to explain:
–Let’s say you have actual wx and time set, and let’s say you are going on a 4 hr flight, and then you accelerate time by 4x. What would have taken 4 hours in normal time now takes 1 hour. So…if you were going to fly for 4 hours and arrive at 1200 noon, what time do you arrive if you have accelerated time by 4? I assume the sim some how adjust for that even if you have accelerated the time and you still arrive at noon.
I need an aspirin.
Well, I know what you mean. 
Using Simrate Bandit, the time in my logbook is reduced if that tells you anything, but I haven’t noticed the time of arrival if I’m honest.
I’ve just loaded a new speedy-uppy thing (I forget its name) that integrates better with the sim, but I haven’t tried it yet.