@Rastin .. During Anahita 4.x testing I realized that performance is bit slow .. I thought it must be because of regex usage for hashtag as well as regex usage in my other functions in views. One of the stackoverflow discussion suggested use of preg_replace_callback. I wrote a small test stub and found that callback is indeed faster.
just fork the master branch to your account, apply the fixes, then create a pull request. It will stay in pending mode until I test and accept it. Start with a very small fix first such as the hashtag plugin.