Thank you BBcan177. I clarified my post a bit, although you answered my questions. So I will modify my configuration as suggested by you:
@BBcan177:
You can define your own GeoIP aliastables by going to the IPv4/6 Tab and in the Source field, add the full path of the GeoIP ISO code.
I have to find that GeoIP ISO code list because a copy pasted table won't be updated.
@BBcan177:
So instead of adding the rules on the NAT rule, create the rules in the Floating Tab or on each individual Interface.
This will hopefully solve this inconsistency:
@ui5-5e:
NAT or rather the corresponding FW rule takes it all (custom port, protocol, block, pass). Thus neither the PfBlockerNG general settings permit/deny etc. nor the PfBlockerNG advance inbound settings (protocol, port-alias) has any impact, as long as they are used in NAT (source) definition.
I thankfully use Pfsense and PfBlockerNG since years :)