This feature request is hard to explain and I think also to implement, so if it is accepted it won't be added in the near future.
When making events, if you want that some conditions affect more than a type than a block, you need to make lots of stack events or conditions.
For example, if you want to make a drill that mines the block under it if it's an ore, you need to make it check if it's iron, gold, diamond, etc. and everytime that you make a new ore you need to redo the event.
I was thinking of a new tab that is a list of all the vanilla and the modded blocks. With this tab you can give to these blocks some extra tags. For example, you give the tag "ore" to iron ore, gold ore, diamond ore, emerald ore, etc. These extra tags are useful for events: when making that drill, instead of checking all the ores, it checks if the block has got the extra tag "ore". And you can add as many extratags to a block as you want.
And it would be cool if that drill could mine blocks of other mods that use the extratag "ore".
I think that this feature will be more useful in MCreator for Minecraft 1.13+ because of the changes in minecraft code.