Since Valorant doesn't have an accept/decline option for queues, I think a great quality of life change is removing instant queue pops. This is mainly to prevent misclicking and queueing the wrong gamemode, or accidently hitting the start button while your friend is still in the washroom.

I think having a 3 second grace period while in queue would be ideal. Basically a queue would not pop until you are at least 3 seconds in. This way you have time to hit the cancel queue button if you misclick something.

Also not to mention but Riot started rolling out punishments for queue dodges so accidental queues are even more punishing.