Possible to split/hide a block without explode?

Hi! I was so slow to put big use of blocks into my rhino workflow but now I am doing it! Anyways, It is often I have an element I want to repeat but on some special places (like the end, in contact with other things etc) I want to edit a block, usually cut it in half or whatever but is there no way to do that without exploding it first?

Another thing regarding blocks. Say I have a block I call FACADE and I design that block and copy paste it to cover all of the facade, lets say I am making it of pallets. I then realize I want the SE facade to be more open and I want to remove 2 of the center planks. At this moment I dont see any other way then just deleting all the blocks except one, explode it, then make the change and then copy paste again. Would be so amazing to somehow change that block on the SE facade and the previous blocks aligned perfectly, they would also update.

Hi Goran - you can define a new block, with more open spacing and then use ReplaceBlock.