So I did my calculations, stripping my character down, and calculating that Hero's Plate with PecoPeco card (+15% max HP, +5% max SP) provides less overall bonus to dragon breath damage compared to glorious Glorious Suit. I did account for 1 SP = 12.5 HP when calculating the ratio for dragon's breath damage. I don't know if my calculations were accurate enough to decide on which armour is better to maximise DB damage.
Also, I did this without any other equipment on that adds MHP/MSP modifiers (e.g. Turkey, Malicious Shadow Set, Ur Seals SP+250, etc..).
I just want to ask what the veterans think of the better armour of choice between the two..without suggesting godlies and MVPs ofc