I've been getting some excellent straight shots with my MCaL using a Guatemalan Finca Agua Tibia I roasted to FC+ 8-10 days past roast. Currently I have the boiler set so it cycles between .95-1.1b. Only had it a week so I haven't played with lower settings yet. It came set to 1.3-1.5b.

I find that with my Cremina, at .9bar, I enjoy almost all the Asian and African SOs. The South American varieties tend to be a bit bright to me. By roasting your own, you should be able to get the roast to a very close agreement with your machine. A suggestion: you can also shut off the heater at whatever point you wish since you have the gauge on your pro. Find the temp for the blend/SO taste you want and then reset your pressurestat. That is a great way to find and enjoy the blends you want to try but are afraid of burning.
Many Happy Pulls
-Richard

Back when I still had my Gaggia Factory I put a digital thermostat on it. Not a PID but a simple thermostat. That way I could change the boiler temperature with the push of a button. I use to run it at a minimal pressure, maybe even lower than 0.8 bar. I would pull my shot, jump the temp up several degrees to get me over one bar and froth, then back down. I could even set it on 150F to keep it warm through the day, then up the temp for pulling a shot and it would was ready in moments, then back to idol. It was a lot of work to mod it and if I had to do it again, I would not. But it was handy on occasion.