I know what you mean, I always used the built-in Excel wizard when I was ingesting general CSVs, and I did take advantage of the ability to babysit the conversion process in steps, to make sure everything was coming out alright, since in this case everything needed to be perfect.

But it has been years and I don't know if there was perfect consistency between different Excel versions.

For structured CSVs which conformed to international standards, I wrote my own code to parse the CSVs with extreme reproducibility so I could avoid manual intervention, but that was a lot more straightforward than the general case would be.

Now I only have Excel on one PC and it's Windows and that one doesn't go on the internet.

If I needed to convert again it would be better to have it in the browser than ever before, especially if it's a CSV that I downloaded on a Linux PC or Mac.