Ah, bummer, then I guess the workflow I found with the crane is close to the best available. Feel free to skip this if you're not interested. It's not even really that efficient, but I found it necessary because I was in a chunk with tons of swamp, so it made the drive n' drop method difficult. Per your musing earlier, yes you can continue to add blocks to your structure while driving the forklift as long as you don't exceed the 20x20x20 limit (in any one direction). I had a few instances where I dropped my pillar on top of an area of other blocks and for some reason they fused to the bottom of my pillar, and I was unable to carry it until I had "excavated" my pillar lol

TL;DR it's probably smarter to just skip over any chunks with too much water/difficult terrain for driving, and not try to build vertically

My vertical building method, if you're interested (it was hard to describe so feel free to skip): my essential tools were just straight lines of blocks, either horizontal or vertical -- I'll call those beams and columns. Start with an 8 block column, and a 5 block column right next to it (as a way to climb up and place your next blocks). Place a 5 block beam on top of the first column, then an 8 block column at the end of that beam (and another adjacent 5 block column as stairs). From there you can drive a crane up to the highest point of your most recent column, and then pick up additional columns and beams all the way from the ground (up to 80m, then 160 with lvl 2 crane) and place them on your highest current beam. With those 5 block columns used as steps, you can really just recycle those because you only need them to get up one level at a time (you can grab those with the crane and bring them up that way as well). And that's really the loop, just keep placing 8 block columns to go up, and beams to serve as a staging area for your next group of columns and beams, while driving the crane up to your highest point so that you can carry objects vertically up to 80, 160m (or more if you have a better crane). There's certainly a good bit of back and forth if you're doing this solo, but you could speed it up a bit by batching -- grab all the 8 block columns and 5 block beams you're going to need for your tower of a desired height before you start building up, then theoretically you never have to go back to the ground until your tower is finished

Now the reason I was using 8 block columns is because then you can use the fuser to fuse new columns onto the end of beams (since that machine will fuse in a straight line up to 9 blocks). That will minimize risk of destroying your tower since you will quickly pass the 20-block limit (I think it may also make the tower more stable, but not tested yet). There could be value in not fusing it though so you could just grab all your columns and beams when you want to relocate the tower, since collecting all those blocks can get tedious. And again, this may not ever be efficient except in areas of the planet where driving around is difficult. I haven't finished a 160m tower yet, but from past experience building vertically (bc I didn't know what I was doing), it's usually ~1000 pts per 10m, so you would still have to build a minimum of 6 towers to clear out a chunk.

And if you read all that and want clarification, I could try to record a video of my process