You can destroy any block (except block 95 (old world border), bedrock and air) in survival instantly by clicking and holding on it when out of survival range but within creative range and then walking/sprinting/flying up to survival range, doing this multiple times in a row without reloading the world won't always destroy the block instantly, it will most likely start mining the block with a lot of progress already done

Yes a have done a search, sorry if this is already reported