You don’t need to be so precise. A good system is ‘robust’ and you can indeed wait until close above entry, or indeed longer if you wish, because any system that require microsecond price monitoring would not be good, so ours was not based on such micro management of trades.
Moreover, what if you miss the entry?
Some traders like to be very specific. If they miss even 1 pip on a 1 day bar which may see a 300 pip move, they would not do it. I do not recommend that attitude.
Others make a judgement, they look at the stop loss and see it is say 40 pips away, so they know a 1 pip difference is fine but a 20 pip is too much. I do not try to set hard and fast rules, but if I were I would say if you missed more than 5% of your stop loss. Now that is an approximation. Remember, your aim is to capture many pips, so missing a few here and there is fine.
As you see these things and practice you get a feel for it.
If you are trading the 1 hour chart for instance on GBPUSD and even if you get in 3 hours later because the price is +/- 10 pips from the entry that is fine by time and distance.