If I understand this thread correctly, if my 1st flight of the trip is BF and doesn't clear the miles will be redeposited to my account.

What then happens to my following flights, one of which (ORD-BOS) has already cleared?

Is UAInsider's info in Post #2 still the policy or do I need to proactively cancel that request so not to get hit for 15K miles to UG such a short segment?

Apologies if this has been recently covered elsewhere, but this was the most onpoint post addressing the BF upgrades in the FAQ.