Nothing's changed - it's just that you missed something that was announced about 8 years ago.
It's always been, since the introduction of power scrolls, that you can gain off an item until your "Theoretical" chance of success was equal to the value of the Powerscroll.
So, if scrolled to 120 skill cap in Tailoring, you can gain off cloth ninja hoods until you would be 120% chance of success.
The crafting gump only displays up to 100%.
However, since you gain 0.2% success chance for every 0.1 skill gained, you can figure out the level you can gain to, by taking the skill level where the item hits 100%, then adding 2.5 skill for every 5 points over 100 your powerscroll was.
This is why you can gain to over 109 (10 points over the non-scrolled cap) using oil cloths, or to 115.0 using cloth ninja hoods (105+10).
The easy way to keep track of it, for Smith & Tailor, is to note that at 100 skill, the chance to craft exceptional is your success chance minus 45% (started at success chance minus 60%, but between 95 & 100 goes up at 250% normal rate, to where it hits 45% at GM, then goes back to normal progression). As a result, you can gain on any item that can be crafted exceptionally, as long as its chance of Exceptional success when crafted by a GM crafter is below 75%. (120% - 45% = 75%)
It works for other skills that have powerscrolls too (besides crafting skills, it's especially useful in relation to Taming and Bard skill gains), but note that not all skills gain at a 2/1 exchange. Some are 5/2 ratio (mostly, non-crafting skills).
