I was recently experimenting with porting some custom editing tools over from .NET to a Python toolbox. At first this was pretty successful and I was pleased with how far I was able to get. However, there is one deal breaker that is preventing us from moving forward with these tools. There is no means in ArcGIS Pro to undo the results of a Python toolbox tool, or a Python script tool.
What I propose is adding the "Enable Undo" functionality available for some geoprocessing tools (e.g., Append) to custom script tools and/or or Python toolboxes. I understand that there any many things that could happen in a Python tool that could not be undone, but if changes are made to the geometry or attributes of a layer or table present in the map, within an edit operation in the script, they should be added to the main undo stack.
Note: apparently there used to be a workaround for this functionality but it is no longer available in 3.x https://community.esri.com/t5/arcgis-pro-questions/how-can-i-enable-quot-undo-edits-quot-for-a-model...
