I understand what you are trying to do and absolutely agree that LogViewPlus should support this level of reporting.
Unfortunately, these types of calculations are currently not possible in LogViewPlus. Aside from the 'Calculate Elapse' command, we also have an 'Elapsed' column - which may help a bit if you can filter your rows appropriately.
There is a lot more we would be doing. In addition to the points above, I would also like to see logger level parsers (to parse message content), "reporting filters" which manipulate the data to a position where reporting can work. I think the whole reporting element of LogViewPlus can be massively improved. I also think this type of reporting should handle multi-threaded scenarios where the sequence of events might be AAA - BBC - CBC. ...if that makes sense.
This is something we are looking at and thinking about, but for now we are still focused on getting data into LogViewPlus. I think we can expect some of these more advanced analysis / reporting features latter in the year and I will make sure our solution can handle the use cases described above.
Thanks for the feedback!