Correct. There's also an eeprom builder option where you can pick a custom list of patches.
The Pythagoras is equivalent to the arachnid, except there are three modes instead of 8. Likewise there are several boards here that all use the Pythagoras just with different eeproms (example radium springs).
All the eeproms on the eeprom category can be dropped in, just realize that some eeproms will only have 3 patches loaded.
Some other fv-1 project on here use a specialized board (example leprechaun, hydra, organ donor). So those aren't availabe in the eeprom category.