I would second this. If you are trying to get the most efficient cannabinoid yield out of your input material, then higher pressure is better. If you are trying to create an extract that still has some nice flavor and a good texture though, it is better to run it at a lower pressure for a longer period of time. In my experience, colder temps and slightly lower pressure (in the primary extraction vessel) produces the best CO2 extract for dabbing purposes. You may need to increase your extraction time by as much as 50% to reach similar yields as running at 1800 PSI.
This is of course assuming you are trying to run the material in a single shot and produce one fraction of oil that is ready for purge then consumption. I personally think that the best CO2 extracts for dabbing are created from a mixture of fractions that are pulled at different conditions.
@hendo253 looks like you are based out of the Tacoma area from that 253 area code, I live in Seattle and run an extraction lab near Olympia. If you want to meet up at some point to talk shop and get some pointers just hit me up. One of my close friends ran a 5L and 20L apeks for a couple of years, so I know some good set points to create pure terpenes, nice wax, (almost) shatter and such straight out of the cup without much further processing needed.