Hey t0qer, I'm glad to hear you're enjoying the Tunneller hack!
Tunneller actually works without using a pathfinder, which means it isn't affected by the usual quirks of pathfinders like Baritone. All of the moving forward, breaking blocks, etc. that is does comes from hand-written logic, which makes its behavior very simple and predictable.
I have experimented with adding a Filler hack in the past, but unfortunately its not as simple as just reversing the Tunneller logic. Let me try to explain:
When breaking a block, you just have to look at it from any side and break it, essentially. But when placing a block, you have to place it against another block that is already there. So to do that, you first have to move the player so that it's looking at the existing block from the right angle, and that angle will be different depending on where you're building. Underground, you can just place blocks against the ceiling and barely move the player at all, but on the surface, there is no ceiling so you have to build from the ground up. And if the "anti-tunnel" you're building is above ground and more than two blocks tall, the player will need to somehow climb up / build stairs to be able to place the blocks at the top.
I hope that makes sense! You can use other hacks like AutoBuild as ZANXEY said, but they are pathfinder-based and will suffer from the usual pathfinder getting stuck / building itself into a corner issues.
