Your description states the following:
Lite Cache works even with commenters, people who left a comment in the past. Other caching plugin usually are not able to serve cached content to commenters creating performance issues on higly partecipative blogs.
The problem is, it doesn't show the commenter his "awaiting moderation" comment. After comment submission, the page reloads and their comment disappears. This can lead to confusion, comment resubmission, and loss of return visitors by folks who do not realize their comment is awaiting moderation.
I know this implementation is intended behavior, but I think it would be preferable to implement what all the other caching plugins do. Disable cache serving to anyone who's recently left a comment. Perhaps, as you say, this can lead to performance issues for heavy comment activity sites, but how many sites really fall into that category? I would suggest, they're in the vast minority, but this implementation is being applied to the majority of sites that would provide a better user experience if this wasn't implemented. Perhaps provide an option for these rare situations instead of forcing the option on all sites.