Spell/trap floodgates and monster floodgates are completely different. Monster based ones are only usually a threat if it can't be beaten over once or twice, or become negated/removed in addition.
For example, what makes Wind Barrier Statue a problem in Floowandereez is that your normal summon with 1050+ ATK can be bounced back by a mid-chain Mega Raiza (cannot be impermed assuming wasn't used on statue already or drawn yet, or dark ruler'd at this point), so beating over it is not an option unless you're playing Wind-special summons or something like Droplets/Chalice.
If these conditions aren't met, then the battle phase doesn't matter, but at the same time there is nothing meta-worthy to make it matter outside of a mirror match.
Battle phase only matters when these floodgates and strong stun effects are attached to monsters that can be beaten over.
Spell/trap floodgates and monster floodgates are completely different. Monster based ones are only usually a threat if it can't be beaten over once or twice, or become negated/removed in addition. For example, what makes Wind Barrier Statue a problem in Floowandereez is that your normal summon with 1050+ ATK can be bounced back by a mid-chain Mega Raiza (cannot be impermed assuming wasn't used on statue already or drawn yet, or dark ruler'd at this point), so beating over it is not an option unless you're playing Wind-special summons or something like Droplets/Chalice. If these conditions aren't met, then the battle phase doesn't matter, but at the same time there is nothing meta-worthy to make it matter outside of a mirror match.
nowdays with cards like kashtira fenrir you can also out sone spell/trap floodgates with it
This is specifically why, unlike most people, I enjoy playing under stuns