I usually build stuff in java, then make a litematica file. Paste that file onto a new flat-world. Then i use chunker to convert the world. I actually never heard of Amulet Editor before but now that i have seen it, i think Chunker is more straightforward.
I use chunker to convert creative maps to bedrock so everyone can enjoy the map wherever they want. (yes i discoverd this only a week ago and i will make the maps i have available on Bedrock)
Little Advice: Your gonna have a mental breakdown if you do this, but you can just remove one mod boot it up and then if nothing occures you got your mod wich crashes the instance. If it chrashes then add the mod back into the folder and try it with another one.
i like to use eol farms, but if you dont want to waste two weeks of your life like i did, then its not suitable for you. you need to dig a perimeter and rmove tenthousands of bedrock. Also to build the farm, you need an light, bat and update supressor. Also you need to link all of the portals up, build a storage system in the nether with item filters because this farm spawns not only creepers but also zombies, skeletons and witches. I highly recommend using shulkerbox loader nad unloader for smth like this, because a double chest wont be enough storage.
Are there any mods like create big cannons ( https://www.curseforge.com/minecraft/mc-mods/create-big-cannons ) , if there are, than it wont be that difficult, but if there arent, then its getting complicated really quikly. If you wanna build an arrow railgun, then you need to time every TNT perfektly, otherwise it will just blow itself up.