I'm pretty sure Tikay will never overcome his blindspot to betting multiples but the Ladbrokes 9am-10am offer is a good example of where you can have good multiples.
The reason we should generally be wary of multiples is that all bets (theoretically) have an inherent advantage to the bookmaker (the overound) and we are multiplying that advantage.
We can have good multiples when we can be 100% sure the advantage is with us, the problem is lot of measurement of who has the edge is subjective.
The one exception is in UNDEROUND or OVERBROKE books where the bookmaker has a -ve advantage. If we can find these and multiply them together we will have a way bigger edge than doing them in singles. We will, of course, increase variance so we need to stake carefully to fit our bankroll, but that is another story.
Every horse that Ladbrokes enhanced was -ev to them and +ev to us as witnessed by the Betfair prices. Therefore multiples would be great.
Even Ladbrokes figured this out and the promotion was limited to singles only. No multiples.
When Ladbrokes are refusing multiples from you then you know they are great bets.
Just trying to break through...