> How does it handle CSVs that are wider or longer than the terminal?

Columns that are exceptionally long but cutting and appending an ellipsis if the line is over 20 characters.

> a built-in grepping feature would make this very useful.

see the following for csv data manipulation:

xsv - Command line csv data manipulation. Rust

csvtk - Command line csv data manipulation. Go

tsv-utils - Command line csv data manipulation toolkit. D

q - Command line csv data manipulation query-like. Python

miller - Command line data manipulation, statistics, and more. C