I also had an off element Awakening in Vincent going the Meltdown route.
My first clear was 1m 05s.
Fujin - Tornado/Raging Storm, USB/Glint(?)
OK - Chain Tornado/Entrust, mUSB/BSB
Vincent - Meltdown/Tornado?, AASB/USB
Elarra - Mages Hymn/Curada(maybe), USB(3?)
Zack - CSB/imperil BSB
I believe this was a majority of my initial setup. My next round of them a week or two ago, I had Fujin's chain so I swapped Zack out for Alphinaud. If you have Alphinaud's Radiant Shield it can help with damage a bit too.
Fujin would use build then use USB and just continue on for the rest of the battle. She may have had her OSB as well but I don't know how much I used it.
OK would mUSB at the start, then follow up with BSB if he had guage around 10s. He may have tossed a single actions worth of guage to Vincent as I was leading Vincent's AASB with his USB for added damage.
Vincent would build up, USB, then AASB, then Meltdown for the rest of the fight.
Elarra would mages hymn and use USB when possible. I can't remember if I had to use her 2nd command or not.
For Zack, I had his IC2/3 LM (it may be on his sphere board) so I would open with the BSB then build for chain. He would throw the chain off around when Fujin and Vincent had gauge. I wasn't able to finish Adamantoise off in one chain so I had to reapply later on.
When I was going through the magicite wheel, I would jump over to reddit and look at the mastery survey threads. If you have time, you can do some searches and see what you have for tools that are comparable. It really helped me with ones I was struggling clearing.