I came across this question on Japanese Quora.
I will also post the text of the question in case the link doesn't work: 「飛行機で、tomato juice without ice, pleaseとお願いしました。CAさんが、no ice？と聞かれました。Yes! と答えました。氷をどばっと入れてくださいました。なぜ？」
I more or less understood it but paused when I got to the「どばっと」part. I wasn't able to find anything on jisho.com but when I searched Japanese Google I found this result on Weblio for synonyms
From what I gather it's just a shortening of the onomatopoeia どばどば? Which I understand that and all the other synonyms provided after searching their definitions; it seems to be conveying a very excited or violent pouring/rushing of water or any liquid for that matter if I got it right.
So in this case what would be the meaning in this question? Am I correct in my understanding that the asker is trying to convey that they received a very large amount of ice in their drink? Or not necessarily a large amount, but just a very enthusiastic pouring of ice into their drink?