So this is a new bug for me. I had previously visited Underworld and started 'You Gotta Shoot Em In The Head', but made no headway (no pun intended?) with it when I came across Bailey's Crossroads. Basically in my role-play (and since there was an initial dialogue in O:A "I'm looking for my dad") I went ahead and stared/completed the quest for that DLC. After emerging from the simulation pod and looting the heck out of the store room I find that 'You Gotta Shoot Em In The Head' is complete, with all ticks check off. I read up on the wiki and some other sources and yeah, it's a bug to do with the Winterized power armor in 'You Gotta Shoot Em In The Head'. I had equipped the armor from O:A and made a save before realizing this quest had "completed".
OKay. So on to my reason for posting. I used the console command 'resetquest ID' to restart 'You Gotta Shoot Em In The Head' (thank goodness for PC console, eh?). My biggest concern is, will this cause problems? I have already FastTraveled to Underworld, and Crowley approached me as though I have never spoken with him but how will the four targets react? I haven't approached any of them for this quest, now and even before I completed O:A, so subsequently before my resetquest command...
If anyone knows how this will play out, please let me know. I'd prefer to get a general idea before I trek across the wasteland and realize it won't work.
Otherwise I guess I will need to load a save WAY before O:A. Thanks!

I guess this is also a good heads up for others. Don't complete O:A before 'You Gotta Shoot Em In The Head' if you want to do that quest in full form!