It would be extremely helpful if you could elaborate on what you are specifically referring to instead of just being generic. These types of comments do not help at all.
The team is working on a fix for situations like this at the moment, but I don't have an ETA to share or any further information just yet.
As it was revealed at SI, there are plans for a Map Veto system. The system will start out in Ranked and Unranked. If the system works well, the team will look into adding it to Quick Match as well. I don't have an ETA to share when that will happen, but it is a possible option!
Interesting balancing idea! From our Designer Notes, Echo is banned about 67% of the time in Plat+ games. Echo is often used to help disrupt plants, so I think having it so Echo can only technically use one blast per plant would help. Do you think Echo has any other frustrating aspects to play against?