There’s an optimization technique where you create a buffer for all the blocks you need, in the right order, and push them off the ledge when the last block shows up. You can see it in passing in my Shuttle Repair GIF on page 5. That’s really the way to approach all the teleporter puzzles, set up a buffer where you get all the parts before you start, and everything gets simpler and more predictable.
Anti-Javelin Battery has some puzzle-specific issues. Most center around analyzing the ratio of blocks you get as input, and seeing what blocks are expendable because you’re going to get an excess of those anyway.
Yes, it’s true that it’s impossible to weld a single block centered on a 3x3 platform. In most puzzles, if you need to do something like that, what you do is construct the 3x3 block out of 3 strips of 3x1, and weld the single block to the center strip before you assemble the 3x3 block.
Anti-Javelin Battery, however, gives you one of those center posts for every gun barrel. The final block contains 6 barrels and one center post. Ergo you must destroy 5 of the 6 you receive. So why not use that?
In my case, what I did was create an assembly of 6 barrels with a strip of those center-post blocks below. I welded the strip to the 3x3 platform, which is easy, and then destroyed the outer two center posts.
Similarly, being frugal with the parts for the 3x3 platform is counterproductive. You get 9 of the blocks for the 3x3 platform per gun barrel. You need 9 per 6 barrels, so you’re going to destroy 5 out of 6 of them. You need to salvage a minimum of 5 of those blocks per damaged shuttle you receive, so shoot for salvaging two 3x1 strips and you’ll have plenty.
As for getting the block count down, think rotators, or conveyor belts with gaps. If you’re moving a large object, you don’t need a continuous belt.
I can post a GIF of my below-100 block solution, but I’m assuming you don’t want that yet.
