The main point is to use zswap over swap plus zram. The sd card usecase definitely doesnt want swap to disk, compressed or otherwise, so zram or no swap are the options.
Exactly. The previous install of the system had no swap at all so enabling zram is an improvement.
Moving swap off of sdcard is indeed a good plan.
But since swapping is done when ram is depleted, using a ramdisk for it (which uses ram) is ... exactly what you dont want.
Since OP states they have disks attached to the machine as well, the better thing is use a partition there for swap.