Determining factor(s) for making creatures robust to square cubed law

Question

Premise and research

I am simply trying to find a reproducible framework for use with creature-design. In my research I have found the larger an animal is, the more likely that animal is to break its bones, generally speaking. Larger animals would need thicker bones to handle the higher stress loads. Furthermore, I learned that heat becomes an issue the larger a creature scales. So heat dissipation traits would be favorable to hedge against the square-cubed law; things like less hair, larger extremities, ect.

Question

Assuming that bone structure/density and heat dissipation traits make the list, what other determining factors are most scientifically relevant to making a creature robust to scaling up without violating the square cubed law?

Note: I'm not asking for an exhaustive list, as that would be too broad. Instead, I'm looking for a small handful of determining factors that would be helpful for a creature designer to scale up his/her creatures while being mindful of the square cubed law.

Further clarifications:

• Desired Scale: undetermined, ideally as big as possible while still allowing the creature to move reasonably well.
• Body Type: I'm mostly interested in bipedal and quadrupedal. You may expand on special considerations for other body types if you want to go really granular with your answer, but I'm not requiring that.
• Biome: terrestrial.
• Everything Else: earth-like
• Scope: I want to stick to known science if possible, but if your list looks too stark, you may include some mildly speculative xenobiology

Answer 1

I can think of 3 elements that might affect it, but I think only the first one is actually the type of thing you were looking for:

1. Geometric orientation of physical structural elements (the actual orientation of the bones, regardless of their actual density, and overall body plan/shape, as it applies to supporting weight):

When you consider the largest land animals ever, of various types, and compare their weight supporting structures, you see 2 main body plans for quadrupeds and 2 for bipeds. For quadrupeds, you see pillars for legs (elephant, rhino, hippo, sauropod dinos, etc), or you see the weight held up primarily by the ground itself (salt water crocodile, elephant seals, etc). For bipeds, you have digitigrade (bird leg) and plantigrade (humans). It's clear that more support structures (more legs) allows greater size, as even T-rex is relatively small compared to large sauropod species, with living species limited to ostrich and humans (or arguably some larger apes like gorillas, though these might be considered more quadrupedal).

2. Diet:

The ability to gain nutrition and calories from a wider variety of food sources (high intake), and make the most of the nutritional content of any given food source (low waste), would lead to maximum growth for any given amount of food, as well as maximum available resources, regardless of which specific variety of resource is present.

3. Respiration/circulation

A likely reason for the reduced size of insects and other land arthropods is falling oxygen levels. These animals stopped being able to get enough oxygen, and properly circulate it through their large bodies. As a result, only the smaller species survived. Very efficient respiratory and circulatory systems would be needed to maintain larger bodies of any type.

In summary: Regardless of the actual structural materials (bones and their density) used, the body plan/shape itself should make support of weight more efficient. It needs to make the most of any and all food. And it needs to be able to get oxygen to all it's parts efficiently.