Alright, so advancement via XP turned out to be less work than I was anticipating. New version is 188.8.131.52, available here
Once you've declared that character generation (chargen) for a particular character is complete, the Character menu changes around a bit. For PCs, there are two "spending modes" - XP or Free. In XP mode, anything you change costs (or refunds) XP or money. In Free mode, you can do whatever. Even exceed racial attribute minimums or maximums, skill caps, and so on.
One note: in XP mode, you can't get rid of attribute points/skill adds/perks that you bought during chargen. You can in Free mode.
You can also reset your character back to the point where it was at when chargen was first completed. I dunno how useful that might be for PCs, but for NPCs it might be good if you're making a unique monster based off of a stock monster, and want to start over.
The other big feature are "Character Events." So that you don't have to switch around between XP and Free mode all the time, I put in menu items for the things that would normally cause you to muck around with your character in unusual ways, like losing a Reality add (possibly down to zero) or a point of Charisma, or gaining free perks. I also added the ability to enchant items as per Asyle's Law of Enchantment, added the ability to generate random items that one might find in Asyle from that same law or from cosm cards (the table is in the GameData XML file and can be customized), and put in hooks for letting the system know that you or your group has played a Glory card. That last one is just for the benefit of perks that require you to have done so. Although the program will also prompt you to add a note to your character describing the glorious scene.
NOW I am taking a break from active development. For reals this time! I still have a few small things on my list, and will work to fix any bugs that crop up. But otherwise I will be getting some sleep...