Yeah, I totally get that! That's why I suggested a plain porn as regex filter. 
It filters every domain with the word porn in it. Regardless if it is porn.domain.com or subdomain.porn.com or 000porn.com (and its subdomains) which is the very first domain my suggested regex filter
(^|\.)[a-z0-9]*porn[a-z0-9]*\.[a-z0-9]{2,63}$
finds in the pi_blocklist_porn_all.list (line 262)
Your suggestion
does not block 000porn.com (on the list) or any of its subdomains (not on the list)!
So it doesn't help @rosaLux161 with their problem.
So for a youth protection filter I still suggest:
Which will even block unknown and newly registered domains regarding porn, sex, ... as well as domains with hyphens, like the very second domain on that list -allporn-.tumblr.com or something like 0-porno.net.
And for some rare cases like Food Porn there's still the whitelist. 
Best regards 