These are updated Quota MUFs. Based on Jessy's quota library, anything build against their lib should also work against this lib. In fact, lib-quota is basically Jessy's but highly modified to make them a little more structurally sensical and to allow them to take cost parameters from system settings rather than hard coding them.
Further, the commands provided here closely match what the commands do 'under the hood' in the server code. Thus, they are fully compatible with @archive dumps (which is the problem I was solving by tweaking Jessy's work). The @-commands are total re-writes by me (Tanabi).
If you have Jessy's quota library already installed, again, it should be totally safe to overwrite it and just use the new @-commands provided.