Late to this thread, but here are my thoughts.

Outside of combos like grab pulse, I think that there are 2 types of pulse bombs: high risk and low risk. High risk pulse bombs are sticks usually on 200 hp heroes that have a lower chance of sticking. Low risk pulse bombs are usually onto tanks. Landing a high risk pulse bomb before a fight usually prevents the team fight.

If I have pulse bomb before a fight starts, I’ll usually try to land a high risk pulse bomb before the fight starts, to completely prevent the team fight. If I’m in the middle of a team fight and my team is losing, going for a high risk pulse bomb might turn the fight in your favor. If you are already winning a fight and just want to secure it, a low risk stick is fine.