When uploading a CSV file, negative values in the Amount column default as 'credits', and positive values default as 'debits'. This means you always have to flip amount type on the 'Review notations' step.

Instead, it would be helpful if it defaulted based on the 'Show debits as negative, credits as positive' preference under Settings. If enabled, then negative values imported from CSV should default as debits, and positive values as credits.