Delayed Blast Fireball and Globe of Invulnerability are both concentration spells; you cannot have the two up at the same time without the other ending before the one takes effect. Other than that, casting DBF while in a Time Stop is an old, tried and true tactic for many editions now: I have a hard time seeing a DM rule that rounds in Time Stop don't count as 'building up' for DBF. Just be sure you don't try to cast another Concentration spell while in Time Stop, as it will end DBF immediately and potentially end Time Stop.
The Globe of Invulnerability is set on a runed pedestal. So it's etched in the runes.Delayed Blast Fireball and Globe of Invulnerability are both concentration spells; you cannot have the two up at the same time without the other ending before the one takes effect. Other than that, casting DBF while in a Time Stop is an old, tried and true tactic for many editions now: I have a hard time seeing a DM rule that rounds in Time Stop don't count as 'building up' for DBF. Just be sure you don't try to cast another Concentration spell while in Time Stop, as it will end DBF immediately and potentially end Time Stop.
The Globe of Invulnerability is set on a runed pedestal. So it's etched in the runes.D'oh! You're correct. I even looked up the spells and missed the concentration.