Ascendant Idol Unpredictable Results
Applying Ascendant idols did not change the item level of a piece until an unstable idol was used. Several ascendant idols were used at 14. When unstable idol was used, rolled to 20. There was NOT a visible attribute for level requirement on the initial item.
Along the same lines, I've seen equipment "jump" 2 levels at a time, which makes using Ascendant Idols risky until level 20 cap, as you run the risk of making currently equipped items unusable for your character.
I'm not sure if both of the above are a display issue on the items or an issue with the actual requirement. In the first case the item could require 20 all along, and not be updating the tooltip. In the second, the tooltip level could be similarly "lagging" until another Ascendant Idol is used, which would look like a jump of 2 levels (typically you end up using several at one time, and I never remember to count how many I actually used).