Thanks for the detailed feedback @snidane!

As maintainer of qsv, here's my reply:

- Given qsv's rapid release cycle (173 releases over three years), the auto-update check is essential at the moment. Once we reach 1.0, I'll turn it off. For now, given your feedback, I've only made it check 10% of the time.

- Pivot is in the backlog and I'll be sure to add unpivot when I implement it. (https://github.com/jqnatividad/qsv/issues/799)

- I'll add a dedicated summing command with the group by (-by) and window by (-over) capability (https://github.com/jqnatividad/qsv/issues/1514). Do note that `stats` has basic sum as @ezequiel-garzon pointed out.

- With the `enum` command, qsv can achieve what you proposed with `laminate`. E.g. qsv enum --new-column newcol --constant newconstant mydata.csv --output laminated-data.csv

- With the cat rowskey command, qsv can already concatenate files with mismatched headers.

- other file formats. qsv supports parquet, csv, tsv, excel, ods, datapackage, sqlite and more (see https://github.com/jqnatividad/qsv/tree/master#file-formats). Fixed-format though is not supported yet and quite interesting, and have added it to the backlog (https://github.com/jqnatividad/qsv/issues/1515)

- as to "enable embedding outputs of commands", qsv is composable by design, so you can use standard stdin/stdout redirection/piping techniques to have it work with other CLI tools like jq, awk, etc.

Finally, just released v0.120.0 that already incorporates the less aggressive self-update check. https://github.com/jqnatividad/qsv/releases/tag/0.120.0