Gaidax you pretty much hit out on the main problem; it's a balance issue. Classes with short rest recovery are based on the idea that they will have more opportunities to recover their resources than those based on long rests. Capping short rests to 1 for each long rest is essentially cutting warlocks and monks off at the knees. The major limitation should be on long rests, as in you have to have been playing for a period of time before you can long rest again. In standard 5e a character can't benefit from more than 1 long rest in 24 hours, but there are no restrictions on short rests. It is seriously problematic balance wise, if it stands then warlocks should get more spells slots, and monks should get more ki and have the ki costs reduced to compensate for fundamental imbalance in their design.
