Hi

First i want You to look at this screen:

 

As You know this is a part of settings panel. I changed it. I think ideas that i present on this screen should be understand when You will see some examples.

Few things of explaination:
Red numbers on the screen match numbers that i will write
DM - doesn't matter
(...) - fixed part of query

example1:
1. No
2.-6. DM (because cronjob is disabled)
Cronjob: disable
Finish query: none

exaple2:
1. Yes
2. Yes
3. 48 (48h=48*60*60=172800s)
4. No
5. DM (seedtime obligation is disable)
6. DM (because only one obligation is enable)
Cronjob: enable
Finish query:

example3:
1. Yes
2. Yes
3. 48 (48h=48*60*60=172800s)
4. Yes
5. 48 (48h=48*60*60=172800s)
6. BOTH
Cronjob: enable
Finish query:

example4:
1. Yes
2. Yes
3. 48 (48h=48*60*60=172800s)
4. Yes
5. 48 (48h=48*60*60=172800s)
6. ONE OF THEM
Cronjob: enable
Finish query:

example5:
1. Yes
2. no
3. DM (ratio obligation is disable)
4. Yes
5. 48 (48h=48*60*60=172800s)
6. DM (because only one obligation is enable)
Cronjob: enable
Finish query:

When number 3. or 5. will be set to 0 the SQL query will be the same that with number bigger than 0 but it will means disable the time limit.

I hope all of this is clear. If no, please post here.

OOh , great one
But for me i suggest xam give away the source code of hit and run cron job so we can edit it to match our own needs , also this screen can be edited and moved to stuff panel to have the ability to edit both of cronjob , and stuff panel front end as a plugin or add-on