Can I decarb after I already made RSO?

Weird title I know, but I’ll clear it up. I had about 12 grams of flower I decarbed for about 30 minutes at 250 degrees. I finished making the RSO just fine, but I’ve noticed it’s not very strong. The stuff I made prior to this batch was a lot stronger even though it was made with trim. So is there a way to stick the RSO in the oven for an amount of time that will convert more of the THC into CBN, which I believe gives me that heavy sedated feeling?

Thanks ahead of time weed bros

Te only way i can see you getting more from the oil is smoking it. That decarbs as you smoke it.
thats a short decarb, i prefer longerwith a lower temp. A good thermometer is paramount as ovens fluctuate in temprature guite a bit with some ovens.
afraid i cant say if you can heat the oils up after making them but someone may help out. It may well be as simple as heating it up and re decarbing it. Did you decarb for the same length of time with the last lot