Rested progress!
For the first time since I started pumping I did a measurement of my erect penis after having rested from pumping for two days. I did the measuring at the end of this sixth week and the result was:
BPEL: 19,1 (7.52 in), which is +0,6 cm (0.24 in) from initial measurements.
MSEG: 13,0 cm (5.12 in), which is +0,5 cm (0.20 in) from initial measurements.

Another first this week was sessions for 20 minutes. I managed to perform three sessions of this length, I cycled the pressure as usual and kept it at 6 inHg most of the time. Towards the end my penis measured 19,9 cm (7.83 in) according to the cylinder's scale.
I hope I'll reach 20 cm in the cylinder soon!

After the 20 minutes of pumping I measured my penis and this was the results:
BPEL 19,5 cm (7.68 in) and MSEG 13,5 cm (5.31 in).
Both measurements are +1,0 cm (0.39 in) compared to initial measurements.

Total pumping this week was 5 sessions: 3 sessions of 20 minutes, 1 session of 15 minutes and 1 session of 10 minutes.