Hi, I remember playing with a mod which featured a transparent block with a white border and multiple options on all sides (+, -, and such). I played it with FTB sky odyssey, but I added it. you had to power the block with redstone and if I'm not mistaken, the mod icon was just the block. it would make an outline of the shape it would build, just like "Build Guide". you could feed it with items by right clicking the block. I've already searched both Modrinth and curseforge (which I likley downloaded it from). I'd appreciate it, if someone found it (or if someone knows a mod for modern mc that does something similar)