Manully tracking code

Hi, thanks for your work, it is awesome plugin 🙂 I have some idea..
If I selected manually tracking code and insert some own, it can be parsed by php via ob_start.

Also, what I want is use apply_filters for whole generated code, for example for replace url of piwik installation ->
https://www.codelibrary.me/2015/05/24/avoid-ad-blockers-with-piwik-analytics/

Thx