I love the idea of this, like Seablock without all the massive complexity of A/B production chains. I've tried playing it and I'm 35 hours' equivalent in (much of it at 5x or 10x speed and afk). I can barely produce anything because almost all of my land is used to create ores and barely any at that. I'm producing about 40 iron ore, 27 copper, and 29 stone per minute. Half of the ore and all of the stone are going to making landfill and I've still only produced 1700 landfill in all this play time. Expanding is painfully slow.

I have a suggestion: Add recipes to use the algae sludge in some way to make landfill, or other tile buildable on water. Wood or coal would be good options in the early game, since with the algae pits, they can both be made in abundance. Another option might be to create bridgelike tiles from plates.

The mod's main chalenge is find a way to create a compact base. I usually make my initial base not completely automated just to save space
Maybe if you use few other mods that help save space it will be easier, my Tesseract for example or merging chests
After you reach bots it will also be much easyer to make a compact base
Maybe I could add an option to make landfill cheaper later but I'm now with few personal problems and it can take some time sorry for that....