Adding this suggestion here on Github so it doesn't get buried again.

I currently only plan to disable some toasts in my modpack, as I do plan to keep some toasts for new modded players.

Main annoyances are the Wizard's Handbook from Electroblob's, and the Traveler's Handbook from Twilight Forest - I'm sure some mods add other specifically-annoying toasts, though. This option to configure which toasts are blocked is mainly so I can block the problematic ones while keep relevant toasts enabled.

ACGaming likely has this feature on his list, just making sure it's on Git too.