But, as far as ice is concerned, it's heavily flawed: all ice is the same, whereas there is water that is shallow enough to cross with units. Since there's no differentiation of depth for ice, you have tanks phasing through solid ground because the front tracks were on 1 inch deep ice. This is still actually a problem and wasn't fixed by removing cold tech.
This isn't exactly accurate. The tanks that sink as you describe on ice is because the difference between the ice (water level) and the ground that a portion of the tank is on is higher than .5 meters (I believe this is the max, but it might be .6, cant remember). You could have a tank drive on ice, have the ice break and NOT SINK, but the way maps are made it currently bugs out hard because the ground level and water level are so drastic in such a short distance.
You could make an entire map with water/ice (for sliding effect on vehicles) that NEVER sink, if done correctly.
I did this on, the 2nd map (?) I had ever streamed and tested, just to see if it worked.
TLDR; the same rules apply for water shallows as they do for ice shallows.