I have released Lesti_Fpc 1.1.5. What is new in this version? I have add a new field in the configurations. Miss Uri Params, not a really creative and good name. The idea behind this parameters is: No request with these parameters will be cached. For example:
It's getting a little bit complicated. All Miss Uri Param will be seperated by comma and every parameter is sperated with an = from a regular expression. Every request with the parameter limit as an integer will miss the Fpc. I know it makes the configurations complexer, but I guess it will help somebody.
The reason why Lesti_Fpc didn't answer at the beginning of magento call is the session. I need the session to make a differents between a category shown with 9 products or a category shown with 15 products. Many people think the limit is always in the uri of an category, but it's just in the moment when a user wants to change the limit. Magento saves this parameter in the session. And if you change to an other category magento knows how much products you want see from the other category. That's why we have Session params in the configurations. If you delete them, the category will be shown allways with 9 products in default. That's the behavior of the most full page caches.
But I have detected an other problem with Session parameters. If the Fpc sends the response, magento can't change for example limit in the session. And so I did have the problem as before. That's why I want to miss every request with limit as an integer.
If you think you didn't need that behavior and want more hits and less misses, you should delete the Session Params and Miss Uri Params
I know that is a lot of configuration for such a small extension and I also didn't like so much fields. I guess I will change this in in version 2 completly and will stop using fields seperated with comma.