When making a syrian rue brew, I assume that there comes a point where reducing it further will cause it to start losing potency.

I recently made a brew using 3g syrian rue. I did 3 boils at one hour each and reduced it to about 3oz. This is the way I usually make a rue brew.

I froze this brew and plan on using it in the near future, but I wonder if I might have reduced it too much. Could I have degraded the potency of the brew by reducing it so much? And if not, what amount of reduction will make a brew start to degrade?

you can evap it down to a resin as long as you don't burn/scald it

I guess that's true. What if the reduction takes place at a rolling boil the entire time? And you take the brew off the stove while it's at a rolling boil and it has been reduced to 3oz?

Should I expect the brew to have lost any potency?

I don't think the rue tea will lose potency due to reducing, harmalas salts are pretty stable, you are evaping the water not the goodies