i think its very important, the higher the pbr is, the higher is the chances people are searching for that exact phrase without any words in the middle or more words

So why not just use exact?

As mentioned above, PBR is only really important if you are doing keyword research using broad match.

This in itself is a huge mistake. When doing keyword research you should always use exact match so that you get real search numbers. I have seen many a campaign ruined by this crucial setting.

As long as you are using exact match, then you don't need to worry about the PBR on your keywords.