Quote from Steve_IB:
I do not think that these filters would cause issues.
For example, point 2.
Lets say you have a buy stop at 15,300 and there is a trade at 15,300. we would check that the ask was at 15,300 or higher at that time. By definition it would be - if 15300 was a valid trade.
Now consider point 3, if bid is 15250, ask is 15251. This filter would check that the last price is between 15,173 and 15,328. So again shouldn't be an issue.