We have been told that the chances of being scanned at ports is dependent on ship "size," so I would say the mass of the ship would likely be a good indicator of the ship size (Anaconda would likely be an exception because it's always .... well ... an outlier !).
So an indication of basic ship mass and some division of "heat emitted per unit ship mass" might give a useful indication of how good the ship is for certain stealth operations. I would suggest a separate Table because otherwise they start to get complicated. I'm not sure which parameter should be used for the heat, however: heat cap, min cooling rate, max cooling rate
Of course, ship mass will change with modules and maybe with some of the engineering features available, but a basic idea might be helpful.