This is more an obvious enhancement than a bug.
Halscope is a really useful tool, and it has the capability of saving data files. (albeit in a rather odd and inefficient format)
It would be very useful (for example when analysing other peoples plots from the mailing list and forum) to be able to load their log files back in to Halscope to zoom in and otherwise analyse.
I think that there is probably no reason to maintain the current format. Just changing it to CSV (or maybe mf4?) would be an improvement in usability.