I was wondering, if something similar could be possible with regex or maybe SQL filter

Currently, the only way to do something like this would be to create a custom analyser.

However, we have recently added SQL capabilities into LogViewPlus.  If we added support for the lag function, we should be able to handle scenarios like this by creating a SQL filter.  This function may not work properly when a log file is in tail mode, but I think it is still a feature worth considering.

I took a quick look into implementing the Lag function.  Unfortunately, there are a few technical issues and I don't think it would be a good fit at this time. 

What I would like to do instead is consider the other issue you raised.   I think LogViewPlus could do a better job of filtering groups of log entries in a single operation.  A lot of the logic necessary to do this already exists in Rules, but this would need to be repackaged to support advanced filtering.  

Thanks for the suggestion,

Toby