GeyserBaseItemCompatibility

Guards custom-item bases that Geyser 2.11 cannot currently override without producing an invalid Bedrock minecraft:block_placer component.

Geyser derives a vanilla block item's custom-item block placer from the Bedrock item identifier. That is normally correct, but the Bedrock item and block registries use different identifiers for banners and redstone: minecraft:banner versus the standing/wall banner blocks, and minecraft:redstone versus minecraft:redstone_wire. Bedrock therefore reports that the derived block cannot be found in its registry.

Geyser's v2 JSON mapping format does not expose a way for a vanilla-item override to suppress or correct the derived Geyser-only block-placer component. Until that upstream limitation changes, omitting these definitions is safer than publishing a client-invalid item registry. The affected Java items continue to work and render with their vanilla icon on Bedrock.