Here's my advice regarding terracore quests, take from it what you will. I've done quite a few recently. It'll depend on your stats of course so adjust accordingly.
Don't spam through rounds- it might be just psychological but from my experience the quicker I tried to progress the more fails I had. 15-30 secs worked best for each round.
With my stats I could go far but didn't go further than 15 I think.
While you might get higher or lower before you complete. This was the amounts rule of thumb I used to complete.
Common - mainly ignore unless you'll get a crate
Uncommon - 10
Rare - 5
Epic - 2
Legendary - lol who you kidding only once in all my tries.
Again if the uncommon or rare is enough to get a crate, probs best to just stop, open it and get more Flux or if lucky something to equip.
Keep an eye on your relic count as you can keep the quests rolling by opening the crates regularly and slowly build up the better relics.
If you're gut tells you to stop at 9 but you're just wanting to push for one more as 10 seems easy, well from experience just complete as 9/10 times my gut was right lmfao.