Where is that recommended? Just enable it and you won't need to add yet another feature to mIRC. The 'keep channel windows open' sounds like exactly the feature you are asking for.....
It's not. At some point the earlier text will be cleared, unless his window buffer is incredibly big, which is not recommended, for sure.
lso - I still don't see the point. logfiles are not for storing stuff you then load into your mIRC, read them offline.
Of course they are. If they weren't, the "Strip codes" logging option wouldn't even exist. How would you read your log files, all filled with bizarre ctrl codes? The answer is "loaded into mIRC". Online or offline, mIRC would be used. And it's almost impossible to load considerably big log files into it. Dividing log files by date and whatsoever is a pain when all you want to do is to search for something in particular. Hence the suggested feature.
But I wouldn't like it to act everytime I open an window. I'd like to have it as a command. A built-in one, of course.. I have my script already doing the job, but it's still slow, depending on how much I load.