I’ve started to work on a new component of the local application to download CSV files. I’ve got a prototype working. It looks as if I can download large files without knowing the ultimate length using HTML chunking, so I’m optimistic that this can be a useful tool to do do long term data analysis with spreadsheets.
Consider this a comment period if you have a particular need for something like that. This won’t be anything too flashy, but should be able to download what you see in graphs over longer periods of time with resonable granularity. I hope to be able to produce files several Mb in size if all goes well.