I just noticed that Datamerge trims leading and trailing spaces from text columns in CSV files when merging. The resulting text doesn't have the proper spaces on either end, even though the spaces are present in the CSV.

This is problematic because if you have two text fields that are being merged in the same text frame without a line break, you can't include a space at the end of one or the start of the other to be inserted between them. You can put a space in between the placeholders, but that won't achieve the desired result if the two fields sometimes need a space and other times don't.