One question I do have is the following: from a hands-on experience point of view, once the stop-loss is triggered, what sell values could one really expect to have in practice?

This will I figure depend on the exchange, the number of buy/sell orders at market value and at a fixed price, the network mempool backlog, etc.
Now in moments of high transactionality, a stop-loss triggered sale order at 11,500 $ may effectively be fulfilled for a lower value depending on the above. So my question here is really, from experience, what kind of effective real values are to be expected in relation to the stop-loss figure you set? (perhaps distinguishing between a bearish moment and a bullish one). Or does the system wait for that exact price to be matched, with no margin of tolerance to the value?

What I had in mind behind the above is to understand if a stop-loss could guarantee the exact parametrized value in a steep quick fall situation, or not.