There will always be 1 tick of slippage if he using market orders (I think he is). I traded NQ using a fully-automated system for several months in 2018. The slippage would be anywhere from -10 to +10 ticks (market moving for or against me after the entry condition was met). However, the average slippage turned out to be just 1 tick, which was the spread 99% of the time.
With Sierra Charts you will not even get that 1 tick spread slippage because the simulator sells to the bid and buys the ask. Most demo accounts give you the last price traded and thus you will have the 1 tick slippage but not with SC. I have carefully monitored it with live trading and sim trading and it is spot on.
The 40 ticks slippage estimate seems to be for the full sized NQ but according to the OP 'Slippage is thru the roof running micro contracts', so god knows what the slippage number must be for MNQ then , 100 ticks???
Like someone said earlier there is high volume on the Micro contracts and it is true. I have traded MNQ while having the entry box on my NQ chart and I get the same fill I would expect from NQ. So any slippage would be about the same on MNQ as NQ. If you are having much slippage you are using the wrong vendors.
I find it's better to over allow for slippage. what some folks might not realize, as you near contract roll over, which start's this Thursday slippage becomes much worse. I have found over the years it's better to over estimate your slippage when designing trading systems with futures.
??? I have been day trading mini futures for the last 15 years, i have never noticed this, has anyone else?
This is true to some extent. But at the same time your system might just be performing well during a specific market environment.