So i've run a bit more experiments : took my save, went in editor, and revealed lots of land, then reloaded, done the same again several time, i've also done this with additionnal mods like toxic armored and explosive biters to have an idea of how much land was required revealed to hope to find stuff. But it was quite saddening, i couldn't find any structure ( beacon/stabilizer), although i was able to find some alien flower and resin ( few and it took long time). I still think it's unintuitive to have to wander above water to find stuff. I resorted to use the black market mod for the stabilizer which is the only thing i needed.
It occured to me that the mining fluid isn't used in the seablock version, so if it was used to generate a seed or a resin, one player would have to set it up for that particular purpose, say something very expensive like 100K mining fluid for 1 seed, something like "deep underground biologic traces research"
I have no idea how difficult it is to edit factorio mods, but the more advanced integration could be an alien planet destination, or maybe another satelite called "biologic sampling satelite" that would yield some organic material (resin or seed )when sent into planets that are not gas giant or "the sun" and very rarely one would receive a building from that planet instead ?
Anyway, it was a fun play ! I found it faster/easier compared to the angel+bob seablock. With the cheapest tech i could finish in around 100 hours while regularly removing and rebuilding part of the base to include newer beacon or module or receipes which i don't generally do, as i just expand and expand.
I made use of the concentrated solar offensive tower heavily as it outrange the worms i had to kill, that may be a "cheese", i died several time before finding out the routine to casually expand with them. Then i used artillery when available, i had one in the middle of my squarish island that fired every 30 sec or so for its entire existence.
I ended up using dirty water as soon as possible and removed all my mineral sludge based ore, only keeping oil from algae. I had the mod "Greentec" too, which adds way of doing bio-based concrete wood fuel or oil product which i found worked well with the seablock to propose alternative receipes in early-midgame.
I only ever used landfill made of stone, turned my slag into it at first, later turned slag from glass into dirty water to void it.
At the end i think i have around 7K/sec production of dirty water installed, but i'm using only 40% or so for science & modules which are taking a high % of ressources. Energy before BHG related was around 20 GW of fusion power, initial 5GW deut/tritium later complemented by 15GW tritium tritium, and a small deut/deut to generate neutrons. I had removed my previous uranium based nuclear plant and all the solar and concentrated solar pannel to make room for more buildings because my island was overall quite small, entirely visible from map view zoom with a grid of 12-16 radars or so.
I think the seablock space constraint is working well with the exotic industries feature of always being able to improve a build with newer modules, newer assemblies, and then swapping an assembly for beacon, and then new beacons and again new module, and new receipes. I had the mod cargo ship active, i had somewhat of an idea to make several island for different things, but i found it more fun to try and not make massive landfill production and many islands and instead trying to fit everything in a single small one and manually tweaking ratios by using the rate calculator mod to handle the math very fast for me ingame. Which retrospectively, again, may explain why it felt exploring a lot of empty water compared to if i had made a larger base with several islands spread apart to make sure i have room to extend them as game goes, in such case i would have found probably a few alien seed or resin "naturally" and then it would have felt logical to continue more exploration for structures.
Anyway, it was a fun game, i added shrek character mod and RP item anarchy, and pretended i was in messy swamp throwing fertilizer from the greentech mod to grow plants while expanding my dirty water production because a playthrough centered around dirty water, made me think of shrek for some reason :).