I have no idea what you're suggesting here... as far as I am aware Pi-Hole is unable to sync adlist repositories, in order to do this I need to custom-write a script that will perform this function. here is the script in case you're interested. this is something Pi-Hole doesn't do at all, much less "quite well".
I'm very grateful for Pi-Hole and all the development that went into it. please don't take my feature request as intimating that Pi-Hole is not awesome, but like all things it can be improved upon. like I said previously, I don't expect much traction on this because is seems that most people don't use Pi-Hole this way, but I have no interest in curating my own adlists, why would I when there's already a few great resources out there like Firebog.net to sync from?
if this feature isn't something deemed "worthy" by the maintainers I'll just continue to double-sync adlists.