Have you had a chance to look at the AutoId Column app (see https://monday.com/marketplace/17). This is is used by over 1.300 monday accounts (not counting the monday partners) and the costs is only a small one-time fee. AutoID Column writes to a normal monday text column and that column can be mirrored as any other column. The prefix is highly customizable and will export to Excel.
We tried the AutoID about 6 months ago for something else, and thusly exhausted the free trial. I think autoID would be the perfect fix, but I can’t showcase it for this use case any more. (This issue came up today).