I think we can discuss this once again. Let me summarize what we want so we are not talking at cross-purposes here:
Where should domains be filtered?
- On the main page
1.1. Top Domains
1.2. Top Blocked/Ads - In the Query Log
Anywhere else?
And then we define a list of regex that are used to do the exclusions. This is of course a very costly process as every domain that is to be shown first needs to get checked. When we add this filter at displaying time, we will not have any effect on the performance-critical point of the DNS resolution.
The effort may be negligible for one regex you are using on a Pi-hole installed on an x86_64 machine but less acceptable for a Raspberry Pi 2B-based Pi-hole and hundred regular expressions. Anyway, we can just try this out and see what happens. In the end, this will only affect those that manually (!) add regular expressions here so nothing that would slow it down for every user.