I'm very sorry I haven't responded, I didn't get alerted to the thread being updated.
I am embarrassed to be reminded of this as I did realise I was being less than observant when I first looked in to it, pfBlocker itself can use multiple lists per alias. To achieve what I described I now do the following - please note I am describing this from memory and I have just started using pfblockerNG instead so please don't…. assume I am correct (!)
In pfBlocker:
Create a new item "Alias_Always_Block"
Add the IP blocklists as required to this - I had missed the fact I could simply click "+" to add multiple lists.
Set as an Alias rather than a permit/deny.
–My "Always Block" contains only a Pe**phile list.
Create a new item "Alias_Mostly_Block"
Add the IP blocklists as required to this.
Set as an Alias rather than a permit/deny.
--My "Mostly Block" contains for example malware and ad lists.
In the pfSense Aliases (Firewall > Aliases> URLs) create an Alias "URLs_pfBlocker_Override" and add the URLs you wish to whitelist.
Now create your firewall rules using aliases in this order, relative to your other rules (I use floating rules).
Block "Alias_Always_Block"
Allow "URLs_pfBlocker_Override"
Block "Alias_Mostly_Block"
Whenever something breaks, add "www.example.com" to the "URLs_pfBlocker_Override" Alias - remember to refresh your rules and wait.
You should now find you never see traffic to Pe**philes, and you may find certain websites get blocked because they are hosted by providers whose entire range has been added to a malware or ad list for some bad apples spoiling the bunch. Manually add them to your override URLs to allow for this.
The above is overly simplified as my actual rules block everything, the URLs override rule only allows HTTP/HTTPS ports, and other allow rules I haven't described get the rest of my legitimate traffic working. I highly recommend reading this thread, I am only half way through it myself but it will explain in detail what I have glossed over here - https://forum.pfsense.org/index.php?topic=78062.0