Experimental WebKit Features

Hi when delving into my iPhone settings I came across Experimental WebKit Features and noticed some of the features were switched on whilst others were not. I am not familiar with the terms or settings on this list and thus began to switch multiple settings to the odd position. Unfortunately I did not take note of which ones I had changed and only came across posts and queries on this topic after doing so. I have since read that they shouldn’t be changed from the default settings however as this has now been changed I am not sure how to reset to the defaults. Can anyone tell me please if in anyway altering the settings would affect the iPhone or performance? I am an iPhone user only and therefore do not require the ability to create or inspect webpages. Please advise thanks!