Hello! Thank you very much for your enthusiasm!
Yeah, I liked increasing the cost for the forgotten slots, I'll probably add it in the final version.
The DL rate is just a reference, I expect the GM to adjust it to their taste, but I think it works well if you use it together with Partials & Criticals so that a super difficult task might fail but still achieve something and a super-easy task succeeds but still give some bad consequences.
I'm very welcome to fan content, please go ahead and make it! I only ask you to wait on the magic supplement stuff until I release mine first (it's already in the works!), but if you make adventures for it please don't hesitate to publish and sell it!
Here is my quick maths on the probability of success/failure assuming an attribute of 11 and a roll greater than DL. The "Prob" column contains the probability of rolling at least that value. So you can see a 50% chance of success/failure with a stat of 11 comes in at DL 21. So I will probably end up using a range of 17, 19, 21, 23, 25+ as that sets the middle at 50% and the upper/lower bounds at about 10%
Regarding fan content: Thank you! I'll start working on some stuff and run it past you when it's in a good place.
Edit: more math! I wrote a little python script to brute force the expected number of uses you can get out of UD. These numbers are in average after 10k iterations.
6: infinity
5: 14
4: 8
3: 5
2: 3
1: 1
0: 0