Just as you think you have spotted all the differences with the stock clock, I noticed the possible snooze repeat intervals are 5/10/20 minutes, whereas in the stock clock it is 5/10/15 minutes.

After changing it to the stock clock interval times, I found out the snooze interval is not saved and will always be 10 minutes. As it is never reported I guess everybody is happy with this snooze interval

I will try to fix it, as soon as I found how the stock clock deals with this.