Anyone interested in helping to maintain/develop/fix/triage the Spreadsheet Workbench. It is getting to be a pretty popular part of users FC workflow and there is a backlog of bugs and feature requests:
issue #4197 - Crash on Recompute With Expression as PropertyString Value
issue #4196 - Expression parser does not allow "/" after first member
issue #4192 - Set an expression with many objects at the same time
issue #4191 - Freecad 0.19pre crashes in spreadsheet
issue #4003 - Renaming spreadsheet no longer has any affect on field tags.
issue #4037 - rewrite unit handling so that unit prefixes will be recognized
issue #4031 - Crash upon solving expression referencing named Constraint
issue #4015 - Expression "jumps" to new object when created
issue #3981 - Add Expression support to certain fields
issue #3925 - Negative numbers with multiple units interpeted as expressions
issue #3839 - Support to update sketch when changing values in a spreadsheet
issue #3696 - Constraints lose values upon reloading file.
issue #3518 - Expressions (fx) not updated
issue #3487 - Add ability to copy objects with expressions linked to spreadsheet
issue #3466 - Control objects visibility via expressions and spreadsheets cells
issue #3460 - Add the following functions to expressions and spreadsheet: concatenate text and indirect
issue #3448 - Failed to parse expression
issue #3391 - Array and dictionary lookup does not work in expressions
issue #3379 - Certain identifiers (like h, rad) cannot be used as names for constraints for usage in expressions
issue #3272 - Failed to parse expression occurs when referencing an alias in an external spreadsheet document
issue #3271 - Relative file references give 'Document not found' unless that file is opened first
issue #3255 - Use consistent angle measure for expressions
issue #2957 - please add spreadsheet direct printing
issue #2766 - Expression link is cuting by creating new object
issue #2477 - Copy of sub objects with expression pointing to a spreadsheet shall not create a new spreadsheet
issue #2474 - Integrate LibreOffice Calc via GUI
issue #2472 - Spreadsheet - Move Cells
issue #2467 - Expression auto-completer slows down FreeCAD
issue #2100 - Spreadsheet: Additional Inverse Display Units
Also, there is a need for better scripting documentation of the Spreadsheet Workbench#Scripting Basics