incremental refresh for Power BI Pro

Yes it is. But you have to use advanced editor. The way I did this was to first load data from an input file into a table. Then I created a second query that loads data from that newly created table. Then I used advanced editor to change the first query in start with the steps from the first query and append the results. And you can avoid duplicate rows by creating a new column with some sort of compound key from your various columns (and later remove this column if you want, once dups are removed).