I've been working on a Strada since the start of the year. With so many variable at your fingertips it is a minefield over and above basic espresso extraction, results can be hard to quantify. With that said, I have learnt more about espresso in the last 4 months then I had in the last 4 years.
Some things that seem to be working for us.
Full puck saturation pre-infusion, you'll need a naked portafilter, pre-infuse until coffee beads on the bottom of the basket. 3-4 bar pressure seems about right otherwise it takes too long, I'm finding about 6-8 seconds. This will have a big effect on the grind you use allowing a much finer grind and helping to increase your extraction. This is also the part of the shot that gives you enhanced body over non-profiled machines.
Higher pressures bring out more brightness, Lower pressures dig into the coffee a bit more sometimes finding good things sometimes not so good and sometimes both. I haven't found much benefit brewing outside of 9.5 to 8 bar range.
In regard to ramping up/ramping down or intra shot curves I still haven't really formed any conclusions. I don't think mimicking a lever style tail of is what you want to do.
Levers have a temperature profile that the pressure roughly matches. Slower flow/lower pressure increases extration, as you have a temperature profile that is extremely flat, any decline in pressure should be moderated. I'm not convinced declining presssure/increased contact time is something you want at the end of a shot when its mainly bitters left in the puck.
If you are going to have a pressure ramp down my feeling is that at ought to be fairly subtle, ie occur within a 1.5 bar range and its purpose is to moderate the way flow normally increases though a shot.
Planning on running some tests in the next couple of weeks to really get on top of those things. I want to set up a test where Ill find a flat pressure that works best for the coffee. Ill then see if I can find a reducing profile that tastes better.
Every action has an opposite reaction that you'll need to compensate for. If the espresso is already dialled in and tasting good, any adjustments you make with pressure will need to be offset with something else, be it grind, extraction time, or temperature, thats where it gets really tricky to manage without wasting too much coffee and or burning out your taste buds.
Good luck. Look forward to hearing your results.