If I am not mistaken, it works differently and does not produce magma unless destroyed. Shall I build multiple liquid spawners, collapse them to make the magma go into one small hole?
Yes, this works OK. Note that it works better if the spawner is on the ground and something caves in on top of it. It works poorly sometimes if the spawner is on top of a pillar surrounded by free space, because the loose magma doesn't like to form in free space (it doesn't make any real sense, it's a dwarf-physics thing).
Best: Spawner on the floor in a hole with just a bit of free space around it (e.g., the 1-tile spawner in a 3x3 pit) -- magma should fill most of the pit
Fine: Spawner on the floor in a tight space (1 tile spawner in a 1x1 pit) -- magma will reliably fill the tile it occupies
Worst: Spawner up in the air on a pillar or something -- magma will still only fill the one square, and also spread out as it falls
I think Dwarf mode also has a version of filling magma tanker carts at workshops, because there is a reaction :
[REACTION:FILL_MAGMATANKER]
[NAME:Fill magmatanker]
[BUILDING:MAGMA_CRUCIBLE:CUSTOM_SHIFT_M]
[BUILDING:MAGMA_SMELTER:CUSTOM_SHIFT_M]
[BUILDING:MAGMA_STEAM_ENGINE:CUSTOM_SHIFT_M]
[BUILDING:MAGMA_ARC_FURNACE:CUSTOM_SHIFT_M]
[BUILDING:BLAST_FURNACE_MAGMA:CUSTOM_SHIFT_M]
[REAGENT:D:1:TOOL:ITEM_TOOL_TANKER:NONE:NONE][EMPTY][PRESERVE_REAGENT]
[PRODUCT:100:3000:LIQUID_MISC:NONE:INORGANIC:NONE][PRODUCT_DIMENSION:150][PRODUCT_TO_CONTAINER:D]
[PRODUCT:100:3000:LIQUID_MISC:NONE:INORGANIC:NONE][PRODUCT_DIMENSION:150][PRODUCT_TO_CONTAINER:D]
[PRODUCT:100:3000:LIQUID_MISC:NONE:INORGANIC:NONE][PRODUCT_DIMENSION:150][PRODUCT_TO_CONTAINER:D]
I don't know for sure how you make the carts, but it looks like it's just a domestic tool so you can forge them.