You measure group temperature.

Also, I use different settings than you. I found that setting it at a higher pressure with a heat break gasket installed and leaving sufficient warm-up time allowed me to pull walk up shots all day, and with good steam power. If you want consistent back-to-back shots, measure group temperature and lock in a cooled portafilter to adjust as I've already documented. These are easy barista skills to learn. As others noted earlier, the Elektra Microcasa a Leva is a home machine. If you want very stable group temperature so you don't have to fuss with that at all, you'll need something like a group with a thermosyphon, which is usually a commercial lever, although sometimes the La Pavoni Eurobar comes up online. Those are temperature-stable and you can control them with a PID. All of these ways of thinking about and dealing with temperature control have been worked through and documented well. Your measurements add to that fund of knowledge along with your exploration of what you're trying to accomplish. I think you've already found the method you like. Set boiler pressure low so you can pull consistent shots and be willing to compromise steaming power. But that is your method, and it is not the only way to work with an MCAL. I don't think the machine is flawed but takes some skill to use because it is a home lever. Some users of machines like this develop a routine after dialing in through measurements or taste so they don't have to measure. An example would be rinsing the portafilter under the tap and locking it in for a minute or so before pulling the next shot.