So in a game today, Beastmaster Vs. Warlock, we had ended a round with 2 Burn on a creature, while the creature also had Regen 2.

The beginning of the next round initiative had passed to the warlock, but during upkeep there was a bit of a problem with what effects would be accounted for in what order.

Would you always calculate damage before other properties during upkeep?

I couldn't find anything about it in the codex, as to whether or not damage takes priority over healing properties during upkeep. This creature had 2 Life left and would have a much better/worse chance of surviving depending on whether it could regenerate before/after taking possible burn damage.

I had ruled that the damage takes priority because it is the Warlock's priority, it would seem to make more sense to have all damage be accounted for during upkeep so as to increase their effectiveness. I'd contest Regen 2 can be a pretty big deal on a 10+ hp creature, so it only seems right that status effects aren't gimped in the only situation they can be partially effective, which is negating regenerative effects and possibly killing someone before they get a chance to recover proper.