I use this setup to get mobile adblock while on Verizon (iOS sadly has never let you override the default DNS server for cellular, just wifi). It works more or less perfectly, albeit with a noticeable hit to device battery life... so much so my wife who otherwise loves PiHole on the home network refuses to use it on her iPhone.

Using iOS's built in support for browser adblockers is largely as effective and doesn't come with the battery life hit.