I'm certainly not a definitive authority on the issue, but I will offer my opinion based on what's worked or me.

I've been quite liberal with carbs. My upper limit has been quite elastic--some days it's 50 while other's it could be as high as 70. I've been losing very consistently over the time span. This is true even since my excercise regimen isn't even that strenuous or vigorous. Only 30 minutes running 5 days/week, and working with weights every other day.

I've added carbs, but not necessarily calories. I've found it difficult adding calories when low carbing and my intake naturally zones in at around 1800/day, give or take fluctuations from day to day.

In my view, working out moderately for an hour at the very least burns about 500 calories. That means, all things being equal, we can eat that much more irrespective if it's made of carbs, protein, or fats--eventhough fats and protein probably has the upper hand in respect to metabolic advantage. Theoretically, since a gram of carb is only 4 calories, if you burn an extra 500/day, even if you add 100 grams of carbs--ALL THINGS BEING EQUAL--you will still lose weight and might even lost faster since the extra fuel will allow you to both workout more vigorously and longer.

Just my views and wishing you the best,

Frederick