Slow down a bit.

Quick review of CO2 physics.

It's too cold at the poles for liquid CO2 most of the time, maybe all of the time.

It's too low pressure near the surface for liquid CO2 all of the time.

Liquid CO2 is ONLY going to be found at reasonable depths (100 metres to 10 km).

The "spiders" are shallow surface features and should perhaps be interpreted as formed by sublimation-related gas escape.

The reasons I'm not happy about drawing parallels with equatorial regions are:

1) things don't look the same

2) It's hard to precipitate dry ice at equatorial lattitudes unless the spin axis tips beyond about 45 degrees. That is possible, but only for about 5% of Mars' history so it's probable that any evidence of it is reworked by other processes.