I think that “free math channel(s)” has been the most requested feature for a long time.
It would also solve things like shunts and current transformers. And let us do more complicated stuff on the fly.
There are couple of ways i think that logging math channel would be possible:
Easiest implementation: Write math-channel formula(s) to log file, so you can remember those in post. If firmware does not allow it, add this information while copying logs to phone. Timestamps etc should pair things nicely, if we have to store this data in two devices.
Bit more complicated to code, easiest to user: Just calculate values for math-channel(s) while copying logs to phone. Bluetooth is so slow, that there should be time to do it while waiting for more. You should end up with log file that has everything ready in one go. Does someone still use card readers, after we got the ability to transfer logs over air?
Logging on the phone might be a possibility, at least for shorter sessions and some kind of data gathering from multiple test points etc. Could get complicated, as suddenly there would be way more processing power and for sure, someone is going to think of some crazy analysis that might be possible…