You can swim in then, and be brought down to half a heart no matter what armour your wearing.
"Full MPS energy shields as well as a bunch of advanced plating for 100% damage reduction, even from void damage?"
Poisen doesn't care.
And neither do splash damage potions.
And the Hot Speings actually (slowly) restore hunger and health, so if you want to permanantly afk somewhere, say an XP farm, you can do this without worries of starvation.
Also liquid poisen looks a lot like the water in certain biomes. Tip, don't go swimming while mining, there's a chance it's poisen.
What other liquids does it add?
The sludge and sewage are MFR, and Sewage can be made into fertarliser and sludge can be put in a sludge boiler to get clay, sand, dirt, soul sand and other things.