@hugo @litchralee_v6 @timbray i use only real routed gua addresses. Since using a different gua internally also mixes up dns views that i despise. I want the same address and only one dns view for a given service.
Access is controlled in the firewall, not by using a non routed ip space.
All isp around here use stable prefixes so the isp gua is reliable. If i was on a unreliable isp i would rather do dynamic dns then use a internal only prefix. imho even a tunneled stable prefix is better.