i could think of a lot of scenarios this would come in use. For example, if you want to create small, detailed statues, create blocks that are a mix of many different blocks, or even extremely compact redstone circuits.,
Wait Little Blocks and Gulliver's Mod 1.12? What universe?
Dunno, looks like Lilliutian seems to be working fine despite being in alpha. Little blocks on the other hand looks dead so while 1.12.2 has "Gulliver", still no little blocks and theres only so much chisel and bits can do since it can't place tiny usable tile entities.