question about the "Open Prices Only" modelling mode in tester

[alex2019trading]

from https://www.mql5.com/en/docs/runtime/testing

it mentioned that when using "open price" in modelling mode

Suppose we test an Expert Advisor on EURUSD H1 in the "Open Prices Only" mode. In this case the total number of ticks (control points) will be no more than 4*number of one-hour bars within the tested interval. But the OnTick() handler is called only at the opening of the one-hour bar. The checks required for a correct testing occur on the rest of the ticks (that are "hidden" from the EA).

• The calculation of margin requirements;
• The triggering of Stop Loss and Take Profit levels;
• The triggering of pending orders;
• The removal of expired pending orders.

if no position, only "open price" would be the control point, but if there is open position, it will use OHLC 4 points to check if stop loss/profit target will be triggered?? if doing so, the stop loss or take profit may still be wrong because we don't know which one occur first (let's say we use longer window like 1hr or daily). can anyone tell if my understanding correct? 

[Fernando Carreiro]

Your topic has been moved to the section: Expert Advisors and Automated Trading
Please consider which section is most appropriate — https://www.mql5.com/en/forum/172166/page6#comment_49114893