My first regeneration was at 18h. But I was using the tractor on the higher gear I could to keep the rpm low. I realized then that it is not a good practice.
Next regens happen at 75h and 128h. I keep the rpm mostly at 1600rpm, now. Regen lasts a few minutes rpms go up a bit and are fluctuating. I just ignore it and continue my work. It does smells weird though!
A rise in the Regen interval is certainly encouraging. I was just a little surprised that my first one was at 24 hours. Getting very antsy for Spring to arrive so I can work it!