The resistances may not show up, but I do know that the health of armor now reflects its resistance ability. For example, with the Cerberus boots, if you assemble them on boots that are less than 50% hp, the resistance to lava/acid is less that 100%, therefore, at least 1 damage point will be dealt to the boots every tile on hazardous terrain.
In conclusion, your resistance to fluids on the floor will be set to 100% resistant when wearing the phase shift set. Correct me if I'm wrong, but damage is calculated by:
HP=(round(damage.points*resistance.asdecimal)-damage.points)-current.hp.percent
So say my boots have a max hp of 10, and I have the phase shift suit on. Say I stepped on lava that deals 12 points of damage. So:
HP=10-(12-round(12*1))
Giving me a total of 10 hp.
If I had 50% resistance on 12 damage lava with full health 10 hp boots:
HP=10-(12-round(12*.5))
Giving me
HP=10-6
HP=4
That's damage calculation (at least for fluids) in a nutshell.