Anything that uses right clicking can be triggered extremely fast, not just block placement. All the following normally includes a delay even if you're holding down the right mouse button.

• Certain projectiles like eggs, snowballs and potions go off like a gatling gun. It also happens with mod items like the throwable brick from Supplementaries, or AE2's matter cannon.
• Blocks that can be interacted with, like doors, bells, levers etc can be triggered at the same speed.
• It also happens with magic spells from mods like Ars Nouveau

This is probably fine for vanilla but it makes mod interaction risky depending on what items a mod adds.

If possible some configuration options would be good, but I understand if that's outside the scope of the mod.

Mod is discontinued now. Thanks for reporting though!

Fixed for the 1.20+ version, thanks!