I'm having some issues between Dea Dia, Cerys and Metal and Stars because of the temperature surface property. (A three way clash between what the mods want to do)

Pressure is what aquillo does for temperature, and dea dia, frozeta, and the journey planets conforms to that.
Unless you explicitly want to select where it should not be used, you want to set the pressure property on your bacteria recipes to be more compatible.

I think that temperature is fine for Cerys compat (that is what it seems to be), but you also want to set a minimum pressure on it so the the rest of us can know what you were thinking when making that recipe.

When I was planning this out, I was more thinking about believability than balance. I can't know what other modded planets have planned, and temperature is a standard implementation from PlanetsLib (and honestly more planets should use it). I mostly just wanted to make sure that extreme thermophile bacteria only grow on hot planets, that things like algae only grow on goldilocks worlds (I did want to make sure algae could work on maraxsis because it felt right to me).

is there a specific combination that bothers you? I don't mind loosening a few things to make it more forgiving, but I'm probably going to keep using temperature

The standard just became the one that the vanilla game uses in the meantime (pressure also meaning temperature).

It is a threeway between Cerys using it to explicitly block certain recipes that I had to try to adjust to kinda out of the blue, (I have a fix already that I discussed with roc, but it is a dumb fix in final fixes). Secretas, journey planets and me are prepared to do it the vanilla way (higher pressure means higher temperature, thicker atmosphere keeping more heat in), and you are only doing it the "special way". (:

It is more robust if you prepare for pressure as well.

The vanilla game does not use pressure as a stand-in for temperature. Most of the planet-restricted crafting is restricted to "X planet only" or to "space/not-space", and uses "property = X number" to do so, at which point they may as well use any property they like. Using other criteria allows us to enable recipes with more flexibility, and allows for crafting on more than 1, but not all planets. temperature could just as easily be "distance from star", or "bacterial hospitability", but I preferred to use one that PlanetsLib established as a norm.
the formula for a planet's robot efficiency (aquilo's robot penalty) is [100 x gravity]/pressure, so modifying a planet's pressure can have unintended consequences.
if you're using PlanetsLib, then leveraging any additional surface property is trivial, and reasonable values are provided for vanilla planets by default.

What was the original problem you were having with M&S and Cerys that prompted this?

Cerys uses this property to hard ban things, so if when I set it on my planet it just banned a recipe from my surface as well. (roc did say that it will need to be updated)

And no, the base game absolutely uses pressure as a property marking surface temperature. (at least as one of the things that it means)
Aquillo, the coldest planet: 300
Fulgora, a little colder than Nauvis: 800
Nauvis: 1000
Gleba with the greenhouse effect: 2000
Vulcanus, clearly the hottest planet: 4000

It is not entirely arbitrary. There is also an in-game mechanic described by wube as "bots struggle in the cold", and that feature is tied to pressure and gravity. Those two alter the energy consumption of logistic and construction bots.