Permanence means one of two things in Ascension. There permanent as in “indefinite duration” and then there’s permanent as in “magic that will last forever”

Indefinite duration is when you pump 6 successes into an effect. The effect is essentially permanent with a few caveats.
1. If the effect is vulgar then it may succumb to the effects of unbelief if witnessed by enough sleepers. While no ruleset is provided for unbelief, a common house rule is that the effect loses a few successes, either becoming weaker or losing duration. Very much up to the ST how that plays...