Hi, Eric. It sounds like there are 2 issues going on here.
In our forums we keep our threads focused on just one issue at a time to ensure we fully answer each of your questions/issues.
In this thread, let’s focus on any bug that might be in tribe_get_upcoming_recurring_event_id_from_url()
For your second item–an easier way to delete instances from a recurrence series–you could request this as a new feature (or maybe search to see if the idea was already posted by someone else) at our plugins’ UserVoice page.
This allows others who are interested in that feature to easily voice their support. We frequently review suggestions there to find out which ones are popular, then we implement as many of them as we can.
If you post it / find it, feel free to link to it from here in case anyone comes across this forum thread in the future.
If you think additional discussion should happen on this topic outside of UserVoice, please create a new thread in this forum.
Thank you and please let me know any additional specifics you have about tribe_get_upcoming_recurring_event_id_from_url()